705 files changed, 40537 insertions, 65528 deletions

diff --git a/.hgignore b/.hgignore
index 967699c..f07b4ba 100644
--- a/.hgignore
+++ b/.hgignore
@@ -1,6 +1,7 @@
 .gdb_history
 .purify
 .svn/
+DS_Store
 Makefile$
 Makefile.pre$
 TAGS$
@@ -17,6 +18,8 @@ platform$
 pyconfig.h$
 python$
 python.exe$
+python-config$
+python-config.py$
 reflog.txt$
 tags$
 Lib/plat-mac/errors.rsrc.df.rsrc
@@ -26,6 +29,7 @@ Doc/tools/jinja/
 Doc/tools/jinja2/
 Doc/tools/pygments/
 Misc/python.pc
+Misc/python-config.sh$
 Modules/Setup$
 Modules/Setup.config
 Modules/Setup.local
diff --git a/Doc/c-api/object.rst b/Doc/c-api/object.rst
index a47183c..02a0d36 100644
--- a/Doc/c-api/object.rst
+++ b/Doc/c-api/object.rst
@@ -342,6 +342,15 @@ is considered sufficient for this determination.
    returned.  This is the equivalent to the Python expression ``len(o)``.
 
 
+.. c:function:: Py_ssize_t PyObject_LengthHint(PyObject *o, Py_ssize_t default)
+
+   Return an estimated length for the object *o*. First trying to return its
+   actual length, then an estimate using ``__length_hint__``, and finally
+   returning the default value. On error ``-1`` is returned. This is the
+   equivalent to the Python expression ``operator.length_hint(o, default)``.
+
+   .. versionadded:: 3.4
+
 .. c:function:: PyObject* PyObject_GetItem(PyObject *o, PyObject *key)
 
    Return element of *o* corresponding to the object *key* or *NULL* on failure.
diff --git a/Doc/faq/library.rst b/Doc/faq/library.rst
index cab2d7b..6a2682f 100644
--- a/Doc/faq/library.rst
+++ b/Doc/faq/library.rst
@@ -209,7 +209,7 @@ using curses, but curses is a fairly large module to learn.
            try:
                c = sys.stdin.read(1)
                print("Got character", repr(c))
-           except IOError:
+           except OSError:
                pass
    finally:
        termios.tcsetattr(fd, termios.TCSAFLUSH, oldterm)
@@ -222,7 +222,11 @@ using curses, but curses is a fairly large module to learn.
    :func:`termios.tcsetattr` turns off stdin's echoing and disables canonical
    mode.  :func:`fcntl.fnctl` is used to obtain stdin's file descriptor flags
    and modify them for non-blocking mode.  Since reading stdin when it is empty
-   results in an :exc:`IOError`, this error is caught and ignored.
+   results in an :exc:`OSError`, this error is caught and ignored.
+
+   .. versionchanged:: 3.3
+      *sys.stdin.read* used to raise :exc:`IOError`. Starting from Python 3.3
+      :exc:`IOError` is alias for :exc:`OSError`.
 
 
 Threads
diff --git a/Doc/howto/logging-cookbook.rst b/Doc/howto/logging-cookbook.rst
index 36a550e..e9e56d6 100644
--- a/Doc/howto/logging-cookbook.rst
+++ b/Doc/howto/logging-cookbook.rst
@@ -741,9 +741,7 @@ the basis for code meeting your own specific requirements::
                     break
                 logger = logging.getLogger(record.name)
                 logger.handle(record) # No level or filter logic applied - just do it!
-            except (KeyboardInterrupt, SystemExit):
-                raise
-            except:
+            except Exception:
                 import sys, traceback
                 print('Whoops! Problem:', file=sys.stderr)
                 traceback.print_exc(file=sys.stderr)
diff --git a/Doc/library/2to3.rst b/Doc/library/2to3.rst
index 97e692f..158b3be 100644
--- a/Doc/library/2to3.rst
+++ b/Doc/library/2to3.rst
@@ -342,6 +342,10 @@ and off individually.  They are described here in more detail.
 
    Handles the move of :func:`reduce` to :func:`functools.reduce`.
 
+.. 2to3fixer:: reload
+
+   Converts :func:`reload` to :func:`imp.reload`.
+
 .. 2to3fixer:: renames
 
    Changes :data:`sys.maxint` to :data:`sys.maxsize`.
diff --git a/Doc/library/abc.rst b/Doc/library/abc.rst
index 6f23596..27abb60 100644
--- a/Doc/library/abc.rst
+++ b/Doc/library/abc.rst
@@ -12,9 +12,9 @@
 --------------
 
 This module provides the infrastructure for defining :term:`abstract base
-classes <abstract base class>` (ABCs) in Python, as outlined in :pep:`3119`; see the PEP for why this
-was added to Python. (See also :pep:`3141` and the :mod:`numbers` module
-regarding a type hierarchy for numbers based on ABCs.)
+classes <abstract base class>` (ABCs) in Python, as outlined in :pep:`3119`;
+see the PEP for why this was added to Python. (See also :pep:`3141` and the
+:mod:`numbers` module regarding a type hierarchy for numbers based on ABCs.)
 
 The :mod:`collections` module has some concrete classes that derive from
 ABCs; these can, of course, be further derived. In addition the
@@ -23,7 +23,7 @@ a class or instance provides a particular interface, for example, is it
 hashable or a mapping.
 
 
-This module provides the following class:
+This module provides the following classes:
 
 .. class:: ABCMeta
 
@@ -127,6 +127,19 @@ This module provides the following class:
    available as a method of ``Foo``, so it is provided separately.
 
 
+.. class:: ABC
+
+   A helper class that has :class:`ABCMeta` as its metaclass.  With this class,
+   an abstract base class can be created by simply deriving from :class:`ABC`,
+   avoiding sometimes confusing metaclass usage.
+
+   Note that the type of :class:`ABC` is still :class:`ABCMeta`, therefore
+   inheriting from :class:`ABC` requires the usual precautions regarding metaclass
+   usage, as multiple inheritance may lead to metaclass conflicts.
+
+   .. versionadded:: 3.4
+
+
 The :mod:`abc` module also provides the following decorators:
 
 .. decorator:: abstractmethod
diff --git a/Doc/library/aifc.rst b/Doc/library/aifc.rst
index 999bad8..f8a6ab7 100644
--- a/Doc/library/aifc.rst
+++ b/Doc/library/aifc.rst
@@ -51,6 +51,10 @@ Module :mod:`aifc` defines the following function:
    used for writing, the file object should be seekable, unless you know ahead of
    time how many samples you are going to write in total and use
    :meth:`writeframesraw` and :meth:`setnframes`.
+   Objects returned by :func:`.open` also supports the :keyword:`with` statement.
+
+.. versionchanged:: 3.4
+   Support for the :keyword:`with` statement was added.
 
 Objects returned by :func:`.open` when a file is opened for reading have the
 following methods:
diff --git a/Doc/library/argparse.rst b/Doc/library/argparse.rst
index ab095e4..7131141 100644
--- a/Doc/library/argparse.rst
+++ b/Doc/library/argparse.rst
@@ -976,9 +976,9 @@ See the section on the default_ keyword argument for information on when the
 ``type`` argument is applied to default arguments.
 
 To ease the use of various types of files, the argparse module provides the
-factory FileType which takes the ``mode=`` and ``bufsize=`` arguments of the
-:func:`open` function.  For example, ``FileType('w')`` can be used to create a
-writable file::
+factory FileType which takes the ``mode=``, ``bufsize=``, ``encoding=`` and
+``errors=`` arguments of the :func:`open` function.  For example,
+``FileType('w')`` can be used to create a writable file::
 
    >>> parser = argparse.ArgumentParser()
    >>> parser.add_argument('bar', type=argparse.FileType('w'))
@@ -1618,17 +1618,19 @@ Sub-commands
 FileType objects
 ^^^^^^^^^^^^^^^^
 
-.. class:: FileType(mode='r', bufsize=None)
+.. class:: FileType(mode='r', bufsize=-1, encoding=None, errors=None)
 
    The :class:`FileType` factory creates objects that can be passed to the type
    argument of :meth:`ArgumentParser.add_argument`.  Arguments that have
-   :class:`FileType` objects as their type will open command-line arguments as files
-   with the requested modes and buffer sizes::
+   :class:`FileType` objects as their type will open command-line arguments as
+   files with the requested modes, buffer sizes, encodings and error handling
+   (see the :func:`open` function for more details)::
 
       >>> parser = argparse.ArgumentParser()
-      >>> parser.add_argument('--output', type=argparse.FileType('wb', 0))
-      >>> parser.parse_args(['--output', 'out'])
-      Namespace(output=<_io.BufferedWriter name='out'>)
+      >>> parser.add_argument('--raw', type=argparse.FileType('wb', 0))
+      >>> parser.add_argument('out', type=argparse.FileType('w', encoding='UTF-8'))
+      >>> parser.parse_args(['--raw', 'raw.dat', 'file.txt'])
+      Namespace(out=<_io.TextIOWrapper name='file.txt' mode='w' encoding='UTF-8'>, raw=<_io.FileIO name='raw.dat' mode='wb'>)
 
    FileType objects understand the pseudo-argument ``'-'`` and automatically
    convert this into ``sys.stdin`` for readable :class:`FileType` objects and
diff --git a/Doc/library/collections.rst b/Doc/library/collections.rst
index 6ef114e..ea4a311 100644
--- a/Doc/library/collections.rst
+++ b/Doc/library/collections.rst
@@ -76,14 +76,19 @@ The class can be used to simulate nested scopes and is useful in templating.
         be modified to change which mappings are searched.  The list should
         always contain at least one mapping.
 
-    .. method:: new_child()
+    .. method:: new_child(m=None)
 
-        Returns a new :class:`ChainMap` containing a new :class:`dict` followed by
-        all of the maps in the current instance.  A call to ``d.new_child()`` is
-        equivalent to: ``ChainMap({}, *d.maps)``.  This method is used for
+        Returns a new :class:`ChainMap` containing a new map followed by
+        all of the maps in the current instance.  If ``m`` is specified,
+        it becomes the new map at the front of the list of mappings; if not
+        specified, an empty dict is used, so that a call to ``d.new_child()``
+        is equivalent to: ``ChainMap({}, *d.maps)``.  This method is used for
         creating subcontexts that can be updated without altering values in any
         of the parent mappings.
 
+        .. versionchanged:: 3.4
+           The optional ``m`` parameter was added.
+
     .. attribute:: parents
 
         Property returning a new :class:`ChainMap` containing all of the maps in
diff --git a/Doc/library/doctest.rst b/Doc/library/doctest.rst
index 222c719..200de45 100644
--- a/Doc/library/doctest.rst
+++ b/Doc/library/doctest.rst
@@ -633,6 +633,16 @@ The second group of options controls how test failures are reported:
    the output is suppressed.
 
 
+.. data:: FAIL_FAST
+
+   When specified, exit after the first failing example and don't attempt to run
+   the remaining examples. Thus, the number of failures reported will be at most
+   1.  This flag may be useful during debugging, since examples after the first
+   failure won't even produce debugging output.
+
+   .. versionadded:: 3.4
+
+
 .. data:: REPORTING_FLAGS
 
    A bitmask or'ing together all the reporting flags above.
diff --git a/Doc/library/exceptions.rst b/Doc/library/exceptions.rst
index 9595221..ece035d 100644
--- a/Doc/library/exceptions.rst
+++ b/Doc/library/exceptions.rst
@@ -260,6 +260,12 @@ The following exceptions are the exceptions that are usually raised.
       :exc:`VMSError`, :exc:`socket.error`, :exc:`select.error` and
       :exc:`mmap.error` have been merged into :exc:`OSError`.
 
+   .. versionchanged:: 3.4
+
+      The :attr:`filename` attribute is now the original file name passed to
+      the function, instead of the name encoded to or decoded from the
+      filesystem encoding.
+
 
 .. exception:: OverflowError
 
diff --git a/Doc/library/filecmp.rst b/Doc/library/filecmp.rst
index 8a88f8c..e5ffefb 100644
--- a/Doc/library/filecmp.rst
+++ b/Doc/library/filecmp.rst
@@ -55,10 +55,10 @@ The :class:`dircmp` class
 
 .. class:: dircmp(a, b, ignore=None, hide=None)
 
-   Construct a new directory comparison object, to compare the directories *a* and
-   *b*. *ignore* is a list of names to ignore, and defaults to ``['RCS', 'CVS',
-   'tags']``. *hide* is a list of names to hide, and defaults to ``[os.curdir,
-   os.pardir]``.
+   Construct a new directory comparison object, to compare the directories *a*
+   and *b*. *ignore* is a list of names to ignore, and defaults to
+   :attr:`filecmp.DEFAULT_IGNORES`. *hide* is a list of names to hide, and
+   defaults to ``[os.curdir, os.pardir]``.
 
    The :class:`dircmp` class compares files by doing *shallow* comparisons
    as described for :func:`filecmp.cmp`.
@@ -164,6 +164,12 @@ The :class:`dircmp` class
       A dictionary mapping names in :attr:`common_dirs` to :class:`dircmp`
       objects.
 
+.. attribute:: DEFAULT_IGNORES
+
+   .. versionadded:: 3.4
+
+   List of directories ignored by :class:`dircmp` by default.
+
 
 Here is a simplified example of using the ``subdirs`` attribute to search
 recursively through two directories to show common different files::
diff --git a/Doc/library/functions.rst b/Doc/library/functions.rst
index 07765ce..64b46a3 100644
--- a/Doc/library/functions.rst
+++ b/Doc/library/functions.rst
@@ -543,6 +543,10 @@ are always available.  They are listed here in alphabetical order.
    :exc:`TypeError` exception is raised if the method is not found or if either
    the *format_spec* or the return value are not strings.
 
+   .. versionadded:: 3.4
+      ``object().__format__(format_spec)`` raises :exc:`TypeError`
+      if *format_spec* is not empty string.
+
 
 .. _func-frozenset:
 .. function:: frozenset([iterable])
@@ -661,6 +665,12 @@ are always available.  They are listed here in alphabetical order.
 
    The integer type is described in :ref:`typesnumeric`.
 
+   .. versionchanged:: 3.4
+      If *base* is not an instance of :class:`int` and the *base* object has a
+      :meth:`base.__index__ <object.__index__>` method, that method is called
+      to obtain an integer for the base.  Previous versions used
+      :meth:`base.__int__ <object.__int__>` instead of :meth:`base.__index__
+      <object.__index__>`.
 
 .. function:: isinstance(object, classinfo)
 
diff --git a/Doc/library/gc.rst b/Doc/library/gc.rst
index 41bda1e..95df2f8 100644
--- a/Doc/library/gc.rst
+++ b/Doc/library/gc.rst
@@ -67,6 +67,24 @@ The :mod:`gc` module provides the following functions:
    returned.
 
 
+.. function:: get_stats()
+
+   Return a list of 3 per-generation dictionaries containing collection
+   statistics since interpreter start.  At this moment, each dictionary will
+   contain the following items:
+
+   * ``collections`` is the number of times this generation was collected;
+
+   * ``collected`` is the total number of objects collected inside this
+     generation;
+
+   * ``uncollectable`` is the total number of objects which were found
+     to be uncollectable (and were therefore moved to the :data:`garbage`
+     list) inside this generation.
+
+   .. versionadded:: 3.4
+
+
 .. function:: set_threshold(threshold0[, threshold1[, threshold2]])
 
    Set the garbage collection thresholds (the collection frequency). Setting
diff --git a/Doc/library/hashlib.rst b/Doc/library/hashlib.rst
index 929d41b..f0fe915 100644
--- a/Doc/library/hashlib.rst
+++ b/Doc/library/hashlib.rst
@@ -51,9 +51,13 @@ concatenation of the data fed to it so far using the :meth:`digest` or
 .. index:: single: OpenSSL; (use in module hashlib)
 
 Constructors for hash algorithms that are always present in this module are
-:func:`md5`, :func:`sha1`, :func:`sha224`, :func:`sha256`, :func:`sha384`, and
-:func:`sha512`.  Additional algorithms may also be available depending upon the
-OpenSSL library that Python uses on your platform.
+:func:`md5`, :func:`sha1`, :func:`sha224`, :func:`sha256`, :func:`sha384`,
+:func:`sha512`, :func:`sha3_224`, :func:`sha3_256`, :func:`sha3_384`, and
+:func:`sha3_512`. Additional algorithms may also be available depending upon
+the OpenSSL library that Python uses on your platform.
+
+   .. versionchanged:: 3.4
+      Add sha3 family of hash algorithms.
 
 For example, to obtain the digest of the byte string ``b'Nobody inspects the
 spammish repetition'``::
diff --git a/Doc/library/http.server.rst b/Doc/library/http.server.rst
index cbad3ed..0577d5e 100644
--- a/Doc/library/http.server.rst
+++ b/Doc/library/http.server.rst
@@ -177,6 +177,9 @@ of which this module provides three different variants:
       complete set of headers is sent, followed by text composed using the
       :attr:`error_message_format` class variable.
 
+      .. versionchanged:: 3.4
+         The error response includes a Content-Length header.
+
    .. method:: send_response(code, message=None)
 
       Adds a response header to the headers buffer and logs the accepted
diff --git a/Doc/library/idle.rst b/Doc/library/idle.rst
index b40e470..c248956 100644
--- a/Doc/library/idle.rst
+++ b/Doc/library/idle.rst
@@ -16,70 +16,82 @@ IDLE has the following features:
 
 * coded in 100% pure Python, using the :mod:`tkinter` GUI toolkit
 
-* cross-platform: works on Windows and Unix
+* cross-platform: works on Windows, Unix, and Mac OS X
 
-* multi-window text editor with multiple undo, Python colorizing and many other
-  features, e.g. smart indent and call tips
+* multi-window text editor with multiple undo, Python colorizing,
+  smart indent, call tips, and many other features
 
 * Python shell window (a.k.a. interactive interpreter)
 
-* debugger (not complete, but you can set breakpoints, view  and step)
+* debugger (not complete, but you can set breakpoints, view and step)
 
 
 Menus
 -----
 
+IDLE has two window types, the Shell window and the Editor window. It is
+possible to have multiple editor windows simultaneously. IDLE's
+menus dynamically change based on which window is currently selected. Each menu
+documented below indicates which window type it is associated with. Click on
+the dotted line at the top of a menu to "tear it off": a separate window
+containing the menu is created (for Unix and Windows only).
 
-File menu
-^^^^^^^^^
+File menu (Shell and Editor)
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 New window
-   create a new editing window
+   Create a new editing window
 
 Open...
-   open an existing file
+   Open an existing file
 
 Open module...
-   open an existing module (searches sys.path)
+   Open an existing module (searches sys.path)
+
+Recent Files
+   Open a list of recent files
 
 Class browser
-   show classes and methods in current file
+   Show classes and methods in current file
 
 Path browser
-   show sys.path directories, modules, classes and methods
+   Show sys.path directories, modules, classes and methods
 
 .. index::
    single: Class browser
    single: Path browser
 
 Save
-   save current window to the associated file (unsaved windows have a \* before and
-   after the window title)
+   Save current window to the associated file (unsaved windows have a
+   \* before and after the window title)
 
 Save As...
-   save current window to new file, which becomes the associated file
+   Save current window to new file, which becomes the associated file
 
 Save Copy As...
-   save current window to different file without changing the associated file
+   Save current window to different file without changing the associated file
+
+Print Window
+   Print the current window
 
 Close
-   close current window (asks to save if unsaved)
+   Close current window (asks to save if unsaved)
 
 Exit
-   close all windows and quit IDLE (asks to save if unsaved)
+   Close all windows and quit IDLE (asks to save if unsaved)
 
 
-Edit menu
-^^^^^^^^^
+Edit menu (Shell and Editor)
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 Undo
-   Undo last change to current window (max 1000 changes)
+   Undo last change to current window (a maximum of 1000 changes may be undone)
 
 Redo
    Redo last undone change to current window
 
 Cut
-   Copy selection into system-wide clipboard; then delete selection
+   Copy selection into system-wide clipboard; then delete the selection
 
 Copy
    Copy selection into system-wide clipboard
@@ -108,11 +120,30 @@ Replace...
 Go to line
    Ask for a line number and show that line
 
+Expand word
+   Expand the word you have typed to match another word in the same buffer;
+   repeat to get a different expansion
+
+Show call tip
+   After an unclosed parenthesis for a function, open a small window with
+   function parameter hints
+
+Show surrounding parens
+   Highlight the surrounding parenthesis
+
+Show Completions
+   Open a scroll window allowing selection keywords and attributes. See
+   Completions below.
+
+
+Format menu (Editor window only)
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
 Indent region
-   Shift selected lines right 4 spaces
+   Shift selected lines right by the indent width (default 4 spaces)
 
 Dedent region
-   Shift selected lines left 4 spaces
+   Shift selected lines left by the indent width (default 4 spaces)
 
 Comment out region
    Insert ## in front of selected lines
@@ -121,67 +152,121 @@ Uncomment region
    Remove leading # or ## from selected lines
 
 Tabify region
-   Turns *leading* stretches of spaces into tabs
+   Turns *leading* stretches of spaces into tabs. (Note: We recommend using
+   4 space blocks to indent Python code.)
 
 Untabify region
-   Turn *all* tabs into the right number of spaces
+   Turn *all* tabs into the correct number of spaces
 
-Expand word
-   Expand the word you have typed to match another word in the same buffer; repeat
-   to get a different expansion
+Toggle tabs
+   Open a dialog to switch between indenting with spaces and tabs.
 
-Format Paragraph
-   Reformat the current blank-line-separated paragraph
+New Indent Width
+   Open a dialog to change indent width. The accepted default by the Python
+   community is 4 spaces.
 
-Import module
-   Import or reload the current module
+Format Paragraph
+   Reformat the current blank-line-separated paragraph. All lines in the
+   paragraph will be formatted to less than 80 columns.
 
-Run script
-   Execute the current file in the __main__ namespace
+Strip trailing whitespace
+   Removes any space characters after the end of the last non-space character
 
 .. index::
    single: Import module
    single: Run script
 
 
-Windows menu
-^^^^^^^^^^^^
+Run menu (Editor window only)
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-Zoom Height
-   toggles the window between normal size (24x80) and maximum height.
+Python Shell
+   Open or wake up the Python Shell window
 
-The rest of this menu lists the names of all open windows; select one to bring
-it to the foreground (deiconifying it if necessary).
+Check module
+   Check the syntax of the module currently open in the Editor window. If the
+   module has not been saved IDLE will prompt the user to save the code.
+
+Run module
+   Restart the shell to clean the environment, then execute the currently
+   open module.  If the module has not been saved IDLE will prompt the user
+   to save the code.
 
+Shell menu (Shell window only)
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-Debug menu
-^^^^^^^^^^
+View Last Restart
+  Scroll the shell window to the last Shell restart
 
-* in the Python Shell window only
+Restart Shell
+  Restart the shell to clean the environment
+
+Debug menu (Shell window only)
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 Go to file/line
    Look around the insert point for a filename and line number, open the file,
    and show the line.  Useful to view the source lines referenced in an
-   exception traceback.
+   exception traceback. Available in the context menu of the Shell window.
 
-Debugger
-   Run commands in the shell under the debugger.
+Debugger (toggle)
+   This feature is not complete and considered experimental. Run commands in
+   the shell under the debugger
 
 Stack viewer
-   Show the stack traceback of the last exception.
+   Show the stack traceback of the last exception
 
 Auto-open Stack Viewer
-   Open stack viewer on traceback.
+   Toggle automatically opening the stack viewer on unhandled exception
 
 .. index::
    single: stack viewer
    single: debugger
 
+Options menu (Shell and Editor)
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Configure IDLE
+   Open a configuration dialog.  Fonts, indentation, keybindings, and color
+   themes may be altered.  Startup Preferences may be set, and additional
+   help sources can be specified.
+
+Code Context (toggle)(Editor Window only)
+   Open a pane at the top of the edit window which shows the block context
+   of the section of code which is scrolling off the top of the window.
+
+Windows menu (Shell and Editor)
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Zoom Height
+   Toggles the window between normal size (40x80 initial setting) and maximum
+   height. The initial size is in the Configure IDLE dialog under the general
+   tab.
+
+The rest of this menu lists the names of all open windows; select one to bring
+it to the foreground (deiconifying it if necessary).
+
+Help menu (Shell and Editor)
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+About IDLE
+   Version, copyright, license, credits
+
+IDLE Help
+   Display a help file for IDLE detailing the menu options, basic editing and
+   navigation, and other tips.
+
+Python Docs
+   Access local Python documentation, if installed. Or will start a web browser
+   and open docs.python.org showing the latest Python documentation.
 
-Edit context menu
-^^^^^^^^^^^^^^^^^
+Additional help sources may be added here with the Configure IDLE dialog under
+the General tab.
 
-* Right-click in Edit window (Control-click on OS X)
+Editor Window context menu
+^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+* Right-click in Editor window (Control-click on OS X)
 
 Cut
    Copy selection into system-wide clipboard; then delete selection
@@ -207,8 +292,8 @@ Clear Breakpoint
    single: breakpoints
 
 
-Shell context menu
-^^^^^^^^^^^^^^^^^^
+Shell Window context menu
+^^^^^^^^^^^^^^^^^^^^^^^^^
 
 * Right-click in Python Shell window (Control-click on OS X)
 
@@ -225,19 +310,44 @@ Go to file/line
    Same as in Debug menu.
 
 
-Basic editing and navigation
-----------------------------
+Editing and navigation
+----------------------
 
 * :kbd:`Backspace` deletes to the left; :kbd:`Del` deletes to the right
 
+* :kbd:`C-Backspace` delete word left; :kbd:`C-Del` delete word to the right
+
 * Arrow keys and :kbd:`Page Up`/:kbd:`Page Down` to move around
 
+* :kbd:`C-LeftArrow` and :kbd:`C-RightArrow` moves by words
+
 * :kbd:`Home`/:kbd:`End` go to begin/end of line
 
 * :kbd:`C-Home`/:kbd:`C-End` go to begin/end of file
 
-* Some :program:`Emacs` bindings may also work, including :kbd:`C-B`,
-  :kbd:`C-P`, :kbd:`C-A`, :kbd:`C-E`, :kbd:`C-D`, :kbd:`C-L`
+* Some useful Emacs bindings are inherited from Tcl/Tk:
+
+   * :kbd:`C-a` beginning of line
+
+   * :kbd:`C-e` end of line
+
+   * :kbd:`C-k` kill line (but doesn't put it in clipboard)
+
+   * :kbd:`C-l` center window around the insertion point
+
+   * :kbd:`C-b` go backwards one character without deleting (usually you can
+     also use the cursor key for this)
+
+   * :kbd:`C-f` go forward one character without deleting (usually you can
+     also use the cursor key for this)
+
+   * :kbd:`C-p` go up one line (usually you can also use the cursor key for
+     this)
+
+   * :kbd:`C-d` delete next character
+
+Standard keybindings (like :kbd:`C-c` to copy and :kbd:`C-v` to paste)
+may work.  Keybindings are selected in the Configure IDLE dialog.
 
 
 Automatic indentation
@@ -246,27 +356,76 @@ Automatic indentation
 After a block-opening statement, the next line is indented by 4 spaces (in the
 Python Shell window by one tab).  After certain keywords (break, return etc.)
 the next line is dedented.  In leading indentation, :kbd:`Backspace` deletes up
-to 4 spaces if they are there. :kbd:`Tab` inserts 1-4 spaces (in the Python
-Shell window one tab). See also the indent/dedent region commands in the edit
-menu.
-
+to 4 spaces if they are there. :kbd:`Tab` inserts spaces (in the Python
+Shell window one tab), number depends on Indent width. Currently tabs
+are restricted to four spaces due to Tcl/Tk limitations.
+
+See also the indent/dedent region commands in the edit menu.
+
+Completions
+^^^^^^^^^^^
+
+Completions are supplied for functions, classes, and attributes of classes,
+both built-in and user-defined. Completions are also provided for
+filenames.
+
+The AutoCompleteWindow (ACW) will open after a predefined delay (default is
+two seconds) after a '.' or (in a string) an os.sep is typed. If after one
+of those characters (plus zero or more other characters) a tab is typed
+the ACW will open immediately if a possible continuation is found.
+
+If there is only one possible completion for the characters entered, a
+:kbd:`Tab` will supply that completion without opening the ACW.
+
+'Show Completions' will force open a completions window, by default the
+:kbd:`C-space` will open a completions window. In an empty
+string, this will contain the files in the current directory. On a
+blank line, it will contain the built-in and user-defined functions and
+classes in the current name spaces, plus any modules imported. If some
+characters have been entered, the ACW will attempt to be more specific.
+
+If a string of characters is typed, the ACW selection will jump to the
+entry most closely matching those characters.  Entering a :kbd:`tab` will
+cause the longest non-ambiguous match to be entered in the Editor window or
+Shell.  Two :kbd:`tab` in a row will supply the current ACW selection, as
+will return or a double click.  Cursor keys, Page Up/Down, mouse selection,
+and the scroll wheel all operate on the ACW.
+
+"Hidden" attributes can be accessed by typing the beginning of hidden
+name after a '.', e.g. '_'. This allows access to modules with
+``__all__`` set, or to class-private attributes.
+
+Completions and the 'Expand Word' facility can save a lot of typing!
+
+Completions are currently limited to those in the namespaces. Names in
+an Editor window which are not via ``__main__`` and :data:`sys.modules` will
+not be found.  Run the module once with your imports to correct this situation.
+Note that IDLE itself places quite a few modules in sys.modules, so
+much can be found by default, e.g. the re module.
+
+If you don't like the ACW popping up unbidden, simply make the delay
+longer or disable the extension.  Or another option is the delay could
+be set to zero. Another alternative to preventing ACW popups is to
+disable the call tips extension.
 
 Python Shell window
 ^^^^^^^^^^^^^^^^^^^
 
-* :kbd:`C-C` interrupts executing command
+* :kbd:`C-c` interrupts executing command
 
-* :kbd:`C-D` sends end-of-file; closes window if typed at a ``>>>`` prompt
+* :kbd:`C-d` sends end-of-file; closes window if typed at a ``>>>`` prompt
+  (this is :kbd:`C-z` on Windows).
 
-* :kbd:`Alt-p` retrieves previous command matching what you have typed
+* :kbd:`Alt-/` (Expand word) is also useful to reduce typing
 
-* :kbd:`Alt-n` retrieves next
+  Command history
 
-* :kbd:`Return` while on any previous command retrieves that command
+  * :kbd:`Alt-p` retrieves previous command matching what you have typed. On
+    OS X use :kbd:`C-p`.
 
-* :kbd:`Alt-/` (Expand word) is also useful here
+  * :kbd:`Alt-n` retrieves next. On OS X use :kbd:`C-n`.
 
-.. index:: single: indentation
+  * :kbd:`Return` while on any previous command retrieves that command
 
 
 Syntax colors
@@ -308,17 +467,17 @@ Startup
 
 Upon startup with the ``-s`` option, IDLE will execute the file referenced by
 the environment variables :envvar:`IDLESTARTUP` or :envvar:`PYTHONSTARTUP`.
-Idle first checks for ``IDLESTARTUP``; if ``IDLESTARTUP`` is present the file
-referenced is run.  If ``IDLESTARTUP`` is not present, Idle checks for
+IDLE first checks for ``IDLESTARTUP``; if ``IDLESTARTUP`` is present the file
+referenced is run.  If ``IDLESTARTUP`` is not present, IDLE checks for
 ``PYTHONSTARTUP``.  Files referenced by these environment variables are
-convenient places to store functions that are used frequently from the Idle
+convenient places to store functions that are used frequently from the IDLE
 shell, or for executing import statements to import common modules.
 
 In addition, ``Tk`` also loads a startup file if it is present.  Note that the
 Tk file is loaded unconditionally.  This additional file is ``.Idle.py`` and is
 looked for in the user's home directory.  Statements in this file will be
 executed in the Tk namespace, so this file is not useful for importing functions
-to be used from Idle's Python shell.
+to be used from IDLE's Python shell.
 
 
 Command line usage
@@ -349,3 +508,45 @@ If there are arguments:
    the arguments are still available in ``sys.argv``.
 
 
+Additional help sources
+-----------------------
+
+IDLE includes a help menu entry called "Python Docs" that will open the
+extensive sources of help, including tutorials, available at docs.python.org.
+Selected URLs can be added or removed from the help menu at any time using the
+Configure IDLE dialog. See the IDLE help option in the help menu of IDLE for
+more information.
+
+
+Other preferences
+-----------------
+
+The font preferences, highlighting, keys, and general preferences can be
+changed via the Configure IDLE menu option.  Be sure to note that
+keys can be user defined, IDLE ships with four built in key sets. In
+addition a user can create a custom key set in the Configure IDLE dialog
+under the keys tab.
+
+Extensions
+----------
+
+IDLE contains an extension facility.  See the beginning of
+config-extensions.def in the idlelib directory for further information.  The
+default extensions are currently:
+
+* FormatParagraph
+
+* AutoExpand
+
+* ZoomHeight
+
+* ScriptBinding
+
+* CallTips
+
+* ParenMatch
+
+* AutoComplete
+
+* CodeContext
+
diff --git a/Doc/library/importlib.rst b/Doc/library/importlib.rst
index 083656e..ee9045b 100644
--- a/Doc/library/importlib.rst
+++ b/Doc/library/importlib.rst
@@ -132,8 +132,6 @@ ABC hierarchy::
                +-- ExecutionLoader --+
                                      +-- FileLoader
                                      +-- SourceLoader
-                                          +-- PyLoader (deprecated)
-                                          +-- PyPycLoader (deprecated)
 
 
 .. class:: Finder
@@ -366,10 +364,12 @@ ABC hierarchy::
     * :meth:`ResourceLoader.get_data`
     * :meth:`ExecutionLoader.get_filename`
           Should only return the path to the source file; sourceless
-          loading is not supported.
+          loading is not supported (see :class:`SourcelessLoader` if that
+          functionality is required)
 
     The abstract methods defined by this class are to add optional bytecode
-    file support. Not implementing these optional methods causes the loader to
+    file support. Not implementing these optional methods (or causing them to
+    raise :exc:`NotImplementedError`) causes the loader to
     only work with source code. Implementing the methods allows the loader to
     work with source *and* bytecode files; it does not allow for *sourceless*
     loading where only bytecode is provided.  Bytecode files are an
@@ -409,6 +409,17 @@ ABC hierarchy::
         When writing to the path fails because the path is read-only
         (:attr:`errno.EACCES`), do not propagate the exception.
 
+    .. method:: source_to_code(data, path)
+
+        Create a code object from Python source.
+
+        The *data* argument can be whatever the :func:`compile` function
+        supports (i.e. string or bytes). The *path* argument should be
+        the "path" to where the source code originated from, which can be an
+        abstract concept (e.g. location in a zip file).
+
+        .. versionadded:: 3.4
+
     .. method:: get_code(fullname)
 
         Concrete implementation of :meth:`InspectLoader.get_code`.
@@ -430,142 +441,6 @@ ABC hierarchy::
         itself does not end in ``__init__``.
 
 
-.. class:: PyLoader
-
-    An abstract base class inheriting from
-    :class:`ExecutionLoader` and
-    :class:`ResourceLoader` designed to ease the loading of
-    Python source modules (bytecode is not handled; see
-    :class:`SourceLoader` for a source/bytecode ABC). A subclass
-    implementing this ABC will only need to worry about exposing how the source
-    code is stored; all other details for loading Python source code will be
-    handled by the concrete implementations of key methods.
-
-    .. deprecated:: 3.2
-        This class has been deprecated in favor of :class:`SourceLoader` and is
-        slated for removal in Python 3.4. See below for how to create a
-        subclass that is compatible with Python 3.1 onwards.
-
-    If compatibility with Python 3.1 is required, then use the following idiom
-    to implement a subclass that will work with Python 3.1 onwards (make sure
-    to implement :meth:`ExecutionLoader.get_filename`)::
-
-        try:
-            from importlib.abc import SourceLoader
-        except ImportError:
-            from importlib.abc import PyLoader as SourceLoader
-
-
-        class CustomLoader(SourceLoader):
-            def get_filename(self, fullname):
-                """Return the path to the source file."""
-                # Implement ...
-
-            def source_path(self, fullname):
-                """Implement source_path in terms of get_filename."""
-                try:
-                    return self.get_filename(fullname)
-                except ImportError:
-                    return None
-
-            def is_package(self, fullname):
-                """Implement is_package by looking for an __init__ file
-                name as returned by get_filename."""
-                filename = os.path.basename(self.get_filename(fullname))
-                return os.path.splitext(filename)[0] == '__init__'
-
-
-    .. method:: source_path(fullname)
-
-        An abstract method that returns the path to the source code for a
-        module. Should return ``None`` if there is no source code.
-        Raises :exc:`ImportError` if the loader knows it cannot handle the
-        module.
-
-    .. method:: get_filename(fullname)
-
-        A concrete implementation of
-        :meth:`importlib.abc.ExecutionLoader.get_filename` that
-        relies on :meth:`source_path`. If :meth:`source_path` returns
-        ``None``, then :exc:`ImportError` is raised.
-
-    .. method:: load_module(fullname)
-
-        A concrete implementation of :meth:`importlib.abc.Loader.load_module`
-        that loads Python source code. All needed information comes from the
-        abstract methods required by this ABC. The only pertinent assumption
-        made by this method is that when loading a package
-        :attr:`__path__` is set to ``[os.path.dirname(__file__)]``.
-
-    .. method:: get_code(fullname)
-
-        A concrete implementation of
-        :meth:`importlib.abc.InspectLoader.get_code` that creates code objects
-        from Python source code, by requesting the source code (using
-        :meth:`source_path` and :meth:`get_data`) and compiling it with the
-        built-in :func:`compile` function.
-
-    .. method:: get_source(fullname)
-
-        A concrete implementation of
-        :meth:`importlib.abc.InspectLoader.get_source`. Uses
-        :meth:`importlib.abc.ResourceLoader.get_data` and :meth:`source_path`
-        to get the source code.  It tries to guess the source encoding using
-        :func:`tokenize.detect_encoding`.
-
-
-.. class:: PyPycLoader
-
-    An abstract base class inheriting from :class:`PyLoader`.
-    This ABC is meant to help in creating loaders that support both Python
-    source and bytecode.
-
-    .. deprecated:: 3.2
-        This class has been deprecated in favor of :class:`SourceLoader` and to
-        properly support :pep:`3147`. If compatibility is required with
-        Python 3.1, implement both :class:`SourceLoader` and :class:`PyLoader`;
-        instructions on how to do so are included in the documentation for
-        :class:`PyLoader`. Do note that this solution will not support
-        sourceless/bytecode-only loading; only source *and* bytecode loading.
-
-    .. versionchanged:: 3.3
-       Updated to parse (but not use) the new source size field in bytecode
-       files when reading and to write out the field properly when writing.
-
-    .. method:: source_mtime(fullname)
-
-        An abstract method which returns the modification time for the source
-        code of the specified module. The modification time should be an
-        integer. If there is no source code, return ``None``. If the
-        module cannot be found then :exc:`ImportError` is raised.
-
-    .. method:: bytecode_path(fullname)
-
-        An abstract method which returns the path to the bytecode for the
-        specified module, if it exists. It returns ``None``
-        if no bytecode exists (yet).
-        Raises :exc:`ImportError` if the loader knows it cannot handle the
-        module.
-
-    .. method:: get_filename(fullname)
-
-        A concrete implementation of
-        :meth:`ExecutionLoader.get_filename` that relies on
-        :meth:`PyLoader.source_path` and :meth:`bytecode_path`.
-        If :meth:`source_path` returns a path, then that value is returned.
-        Else if :meth:`bytecode_path` returns a path, that path will be
-        returned. If a path is not available from both methods,
-        :exc:`ImportError` is raised.
-
-    .. method:: write_bytecode(fullname, bytecode)
-
-        An abstract method which has the loader write *bytecode* for future
-        use. If the bytecode is written, return ``True``. Return
-        ``False`` if the bytecode could not be written. This method
-        should not be called if :data:`sys.dont_write_bytecode` is true.
-        The *bytecode* argument should be a bytes string or bytes array.
-
-
 :mod:`importlib.machinery` -- Importers and path hooks
 ------------------------------------------------------
 
diff --git a/Doc/library/json.rst b/Doc/library/json.rst
index bdb6436..25a3358 100644
--- a/Doc/library/json.rst
+++ b/Doc/library/json.rst
@@ -42,8 +42,7 @@ Compact encoding::
 Pretty printing::
 
     >>> import json
-    >>> print(json.dumps({'4': 5, '6': 7}, sort_keys=True,
-    ...                  indent=4, separators=(',', ': ')))
+    >>> print(json.dumps({'4': 5, '6': 7}, sort_keys=True, indent=4))
     {
         "4": 5,
         "6": 7
@@ -156,15 +155,13 @@ Basic Usage
    .. versionchanged:: 3.2
       Allow strings for *indent* in addition to integers.
 
-   .. note::
-
-      Since the default item separator is ``', '``,  the output might include
-      trailing whitespace when *indent* is specified.  You can use
-      ``separators=(',', ': ')`` to avoid this.
+   If specified, *separators* should be an ``(item_separator, key_separator)``
+   tuple.  The default is ``(', ', ': ')`` if *indent* is ``None`` and
+   ``(',', ': ')`` otherwise.  To get the most compact JSON representation,
+   you should specify ``(',', ':')`` to eliminate whitespace.
 
-   If *separators* is an ``(item_separator, dict_separator)`` tuple, then it
-   will be used instead of the default ``(', ', ': ')`` separators.  ``(',',
-   ':')`` is the most compact JSON representation.
+   .. versionchanged:: 3.4
+      Use ``(',', ': ')`` as default if *indent* is not ``None``.
 
    *default(obj)* is a function that should return a serializable version of
    *obj* or raise :exc:`TypeError`.  The default simply raises :exc:`TypeError`.
@@ -400,15 +397,13 @@ Encoders and Decoders
    .. versionchanged:: 3.2
       Allow strings for *indent* in addition to integers.
 
-   .. note::
-
-      Since the default item separator is ``', '``,  the output might include
-      trailing whitespace when *indent* is specified.  You can use
-      ``separators=(',', ': ')`` to avoid this.
-
    If specified, *separators* should be an ``(item_separator, key_separator)``
-   tuple.  The default is ``(', ', ': ')``.  To get the most compact JSON
-   representation, you should specify ``(',', ':')`` to eliminate whitespace.
+   tuple.  The default is ``(', ', ': ')`` if *indent* is ``None`` and
+   ``(',', ': ')`` otherwise.  To get the most compact JSON representation,
+   you should specify ``(',', ':')`` to eliminate whitespace.
+
+   .. versionchanged:: 3.4
+      Use ``(',', ': ')`` as default if *indent* is not ``None``.
 
    If specified, *default* is a function that gets called for objects that can't
    otherwise be serialized.  It should return a JSON encodable version of the
diff --git a/Doc/library/logging.config.rst b/Doc/library/logging.config.rst
index 1391ed2..16d3294 100644
--- a/Doc/library/logging.config.rst
+++ b/Doc/library/logging.config.rst
@@ -76,11 +76,23 @@ in :mod:`logging` itself) and defining handlers which are declared either in
 
 .. function:: fileConfig(fname, defaults=None, disable_existing_loggers=True)
 
-   Reads the logging configuration from a :mod:`configparser`\-format file
-   named *fname*. This function can be called several times from an
-   application, allowing an end user to select from various pre-canned
-   configurations (if the developer provides a mechanism to present the choices
-   and load the chosen configuration).
+   Reads the logging configuration from a :mod:`configparser`\-format file.
+   This function can be called several times from an application, allowing an
+   end user to select from various pre-canned configurations (if the developer
+   provides a mechanism to present the choices and load the chosen
+   configuration).
+
+   :param fname: A filename, or a file-like object, or an instance derived
+                 from :class:`~configparser.RawConfigParser`. If a
+                 ``RawConfigParser``-derived instance is passed, it is used as
+                 is. Otherwise, a :class:`~configparser.Configparser` is
+                 instantiated, and the configuration read by it from the
+                 object passed in ``fname``. If that has a :meth:`readline`
+                 method, it is assumed to be a file-like object and read using
+                 :meth:`~configparser.ConfigParser.read_file`; otherwise,
+                 it is assumed to be a filename and passed to
+                 :meth:`~configparser.ConfigParser.read`.
+
 
    :param defaults: Defaults to be passed to the ConfigParser can be specified
                     in this argument.
@@ -94,8 +106,17 @@ in :mod:`logging` itself) and defining handlers which are declared either in
                                     their ancestors are explicitly named in the
                                     logging configuration.
 
+   .. versionchanged:: 3.4
+      An instance of a subclass of :class:`~configparser.RawConfigParser` is
+      now accepted as a value for ``fname``. This facilitates:
+
+      * Use of a configuration file where logging configuration is just part
+        of the overall application configuration.
+      * Use of a configuration read from a file, and then modified by the using
+        application (e.g. based on command-line parameters or other aspects
+        of the runtime environment) before being passed to ``fileConfig``.
 
-.. function:: listen(port=DEFAULT_LOGGING_CONFIG_PORT)
+.. function:: listen(port=DEFAULT_LOGGING_CONFIG_PORT, verify=None)
 
    Starts up a socket server on the specified port, and listens for new
    configurations. If no port is specified, the module's default
@@ -105,6 +126,17 @@ in :mod:`logging` itself) and defining handlers which are declared either in
    server, and which you can :meth:`join` when appropriate. To stop the server,
    call :func:`stopListening`.
 
+   The ``verify`` argument, if specified, should be a callable which should
+   verify whether bytes received across the socket are valid and should be
+   processed. This could be done by encrypting and/or signing what is sent
+   across the socket, such that the ``verify`` callable can perform
+   signature verification and/or decryption. The ``verify`` callable is called
+   with a single argument - the bytes received across the socket - and should
+   return the bytes to be processed, or None to indicate that the bytes should
+   be discarded. The returned bytes could be the same as the passed in bytes
+   (e.g. when only verification is done), or they could be completely different
+   (perhaps if decryption were performed).
+
    To send a configuration to the socket, read in the configuration file and
    send it to the socket as a string of bytes preceded by a four-byte length
    string packed in binary using ``struct.pack('>L', n)``.
@@ -121,7 +153,12 @@ in :mod:`logging` itself) and defining handlers which are declared either in
       :func:`listen` socket and sending a configuration which runs whatever
       code the attacker wants to have executed in the victim's process. This is
       especially easy to do if the default port is used, but not hard even if a
-      different port is used).
+      different port is used). To avoid the risk of this happening, use the
+      ``verify`` argument to :func:`listen` to prevent unrecognised
+      configurations from being applied.
+
+   .. versionchanged:: 3.4.
+      The ``verify`` argument was added.
 
 .. function:: stopListening()
 
diff --git a/Doc/library/nntplib.rst b/Doc/library/nntplib.rst
index 87a50b0..5977d2a 100644
--- a/Doc/library/nntplib.rst
+++ b/Doc/library/nntplib.rst
@@ -1,4 +1,3 @@
-
 :mod:`nntplib` --- NNTP protocol client
 =======================================
 
@@ -71,7 +70,7 @@ The module itself defines the following classes:
    reader-specific commands, such as ``group``.  If you get unexpected
    :exc:`NNTPPermanentError`\ s, you might need to set *readermode*.
    :class:`NNTP` class supports the :keyword:`with` statement to
-   unconditionally consume :exc:`socket.error` exceptions and to close the NNTP
+   unconditionally consume :exc:`OSError` exceptions and to close the NNTP
    connection when done. Here is a sample on how using it:
 
     >>> from nntplib import NNTP
diff --git a/Doc/library/operator.rst b/Doc/library/operator.rst
index 3860880..877a790 100644
--- a/Doc/library/operator.rst
+++ b/Doc/library/operator.rst
@@ -235,6 +235,14 @@ their character equivalents.
 
 .. XXX: find a better, readable, example
 
+.. function:: length_hint(obj, default=0)
+
+   Return an estimated length for the object *o*. First trying to return its
+   actual length, then an estimate using :meth:`object.__length_hint__`, and
+   finally returning the default value.
+
+   .. versionadded:: 3.4
+
 The :mod:`operator` module also defines tools for generalized attribute and item
 lookups.  These are useful for making fast field extractors as arguments for
 :func:`map`, :func:`sorted`, :meth:`itertools.groupby`, or other functions that
diff --git a/Doc/library/os.path.rst b/Doc/library/os.path.rst
index 36a61a5..0f63849 100644
--- a/Doc/library/os.path.rst
+++ b/Doc/library/os.path.rst
@@ -42,7 +42,6 @@ the :mod:`glob` module.)
    * :mod:`posixpath` for UNIX-style paths
    * :mod:`ntpath` for Windows paths
    * :mod:`macpath` for old-style MacOS paths
-   * :mod:`os2emxpath` for OS/2 EMX paths
 
 
 .. function:: abspath(path)
@@ -250,15 +249,14 @@ the :mod:`glob` module.)
    On Unix, this is determined by the device number and i-node number and raises an
    exception if a :func:`os.stat` call on either pathname fails.
 
-   On Windows, two files are the same if they resolve to the same final path
-   name using the Windows API call GetFinalPathNameByHandle. This function
-   raises an exception if handles cannot be obtained to either file.
-
    Availability: Unix, Windows.
 
    .. versionchanged:: 3.2
       Added Windows support.
 
+   .. versionchanged:: 3.4
+      Windows now uses the same implementation as all other platforms.
+
 
 .. function:: sameopenfile(fp1, fp2)
 
@@ -277,7 +275,10 @@ the :mod:`glob` module.)
    :func:`stat`.  This function implements the underlying comparison used by
    :func:`samefile` and :func:`sameopenfile`.
 
-   Availability: Unix.
+   Availability: Unix, Windows.
+
+   .. versionchanged:: 3.4
+      Added Windows support.
 
 
 .. function:: split(path)
diff --git a/Doc/library/os.rst b/Doc/library/os.rst
index 027ad70..d2f7d01 100644
--- a/Doc/library/os.rst
+++ b/Doc/library/os.rst
@@ -54,7 +54,7 @@ Notes on the availability of these functions:
 
    The name of the operating system dependent module imported.  The following
    names have currently been registered: ``'posix'``, ``'nt'``, ``'mac'``,
-   ``'os2'``, ``'ce'``, ``'java'``.
+   ``'ce'``, ``'java'``.
 
    .. seealso::
       :attr:`sys.platform` has a finer granularity.  :func:`os.uname` gives
diff --git a/Doc/library/poplib.rst b/Doc/library/poplib.rst
index b4080d6..e248d6b 100644
--- a/Doc/library/poplib.rst
+++ b/Doc/library/poplib.rst
@@ -13,8 +13,11 @@
 --------------
 
 This module defines a class, :class:`POP3`, which encapsulates a connection to a
-POP3 server and implements the protocol as defined in :rfc:`1725`.  The
-:class:`POP3` class supports both the minimal and optional command sets.
+POP3 server and implements the protocol as defined in :rfc:`1939`. The
+:class:`POP3` class supports both the minimal and optional command sets from
+:rfc:`1939`. The :class:`POP3` class also supports the `STLS` command introduced
+in :rfc:`2595` to enable encrypted communication on an already established connection.
+
 Additionally, this module provides a class :class:`POP3_SSL`, which provides
 support for connecting to POP3 servers that use SSL as an underlying protocol
 layer.
@@ -97,6 +100,14 @@ An :class:`POP3` instance has the following methods:
    Returns the greeting string sent by the POP3 server.
 
 
+.. method:: POP3.capa()
+
+   Query the server's capabilities as specified in :rfc:`2449`.
+   Returns a dictionary in the form ``{'name': ['param'...]}``.
+
+   .. versionadded:: 3.4
+
+
 .. method:: POP3.user(username)
 
    Send user command, response should indicate that a password is required.
@@ -176,6 +187,18 @@ An :class:`POP3` instance has the following methods:
    the unique id for that message in the form ``'response mesgnum uid``, otherwise
    result is list ``(response, ['mesgnum uid', ...], octets)``.
 
+.. method:: POP3.stls(context=None)
+
+   Start a TLS session on the active connection as specified in :rfc:`2595`.
+   This is only allowed before user authentication
+
+   *context* parameter is a :class:`ssl.SSLContext` object which allows
+   bundling SSL configuration options, certificates and private keys into
+   a single (potentially long-lived) structure.
+
+   .. versionadded:: 3.4
+
+
 Instances of :class:`POP3_SSL` have no additional methods. The interface of this
 subclass is identical to its parent.
 
diff --git a/Doc/library/pty.rst b/Doc/library/pty.rst
index 2b9385b..90baec5 100644
--- a/Doc/library/pty.rst
+++ b/Doc/library/pty.rst
@@ -45,6 +45,9 @@ The :mod:`pty` module defines the following functions:
    a file descriptor. The defaults try to read 1024 bytes each time they are
    called.
 
+   .. versionchanged:: 3.4
+      :func:`spawn` now returns the status value from :func:`os.waitpid`
+      on the child process.
 
 Example
 -------
diff --git a/Doc/library/select.rst b/Doc/library/select.rst
index 4e60f4a..b73f11e 100644
--- a/Doc/library/select.rst
+++ b/Doc/library/select.rst
@@ -47,11 +47,14 @@ The module defines the following:
    to :const:`EPOLL_CLOEXEC`, which causes the epoll descriptor to be closed
    automatically when :func:`os.execve` is called. See section
    :ref:`epoll-objects` below for the methods supported by epolling objects.
-
+   They also support the :keyword:`with` statement.
 
    .. versionchanged:: 3.3
       Added the *flags* parameter.
 
+   .. versionchanged:: 3.4
+      Support for the :keyword:`with` statement was added.
+
 
 .. function:: poll()
 
diff --git a/Doc/library/shelve.rst b/Doc/library/shelve.rst
index 9d7d504..b60a548 100644
--- a/Doc/library/shelve.rst
+++ b/Doc/library/shelve.rst
@@ -44,8 +44,11 @@ lots of shared  sub-objects.  The keys are ordinary strings.
    .. note::
 
       Do not rely on the shelf being closed automatically; always call
-      :meth:`close` explicitly when you don't need it any more, or use a
-      :keyword:`with` statement with :func:`contextlib.closing`.
+      :meth:`~Shelf.close` explicitly when you don't need it any more, or
+      use :func:`shelve.open` as a context manager::
+
+          with shelve.open('spam') as db:
+              db['eggs'] = 'eggs'
 
 .. warning::
 
@@ -118,10 +121,15 @@ Restrictions
    The *keyencoding* parameter is the encoding used to encode keys before they
    are used with the underlying dict.
 
-   .. versionadded:: 3.2
-      The *keyencoding* parameter; previously, keys were always encoded in
+   :class:`Shelf` objects can also be used as context managers.
+
+   .. versionchanged:: 3.2
+      Added the *keyencoding* parameter; previously, keys were always encoded in
       UTF-8.
 
+   .. versionchanged:: 3.4
+      Added context manager support.
+
 
 .. class:: BsdDbShelf(dict, protocol=None, writeback=False, keyencoding='utf-8')
 
diff --git a/Doc/library/shutil.rst b/Doc/library/shutil.rst
index a1457d0..e4f348c 100644
--- a/Doc/library/shutil.rst
+++ b/Doc/library/shutil.rst
@@ -53,7 +53,7 @@ Directory and files operations
    *dst* and return *dst*.  *src* and *dst* are path names given as strings.
    *dst* must be the complete target file name; look at :func:`shutil.copy`
    for a copy that accepts a target directory path.  If *src* and *dst*
-   specify the same file, :exc:`Error` is raised.
+   specify the same file, :exc:`SameFileError` is raised.
 
    The destination location must be writable; otherwise, an :exc:`OSError`
    exception will be raised. If *dst* already exists, it will be replaced.
@@ -69,6 +69,19 @@ Directory and files operations
       Added *follow_symlinks* argument.
       Now returns *dst*.
 
+   .. versionchanged:: 3.4
+      Raise :exc:`SameFileError` instead of :exc:`Error`.  Since the former is
+      a subclass of the latter, this change is backward compatible.
+
+
+.. exception:: SameFileError
+
+   This exception is raised if source and destination in :func:`copyfile`
+   are the same file.
+
+   .. versionadded:: 3.4
+
+
 .. function:: copymode(src, dst, *, follow_symlinks=True)
 
    Copy the permission bits from *src* to *dst*.  The file contents, owner, and
@@ -380,11 +393,10 @@ provided by this module. ::
                errors.extend(err.args[0])
        try:
            copystat(src, dst)
-       except WindowsError:
-           # can't copy file access times on Windows
-           pass
        except OSError as why:
-           errors.extend((src, dst, str(why)))
+           # can't copy file access times on Windows
+           if why.winerror is None:
+               errors.extend((src, dst, str(why)))
        if errors:
            raise Error(errors)
 
diff --git a/Doc/library/socket.rst b/Doc/library/socket.rst
index 5737b40..5a6bc1d 100644
--- a/Doc/library/socket.rst
+++ b/Doc/library/socket.rst
@@ -107,8 +107,8 @@ created.  Socket addresses are represented as follows:
 
   .. versionadded:: 3.3
 
-- Certain other address families (:const:`AF_BLUETOOTH`, :const:`AF_PACKET`)
-  support specific representations.
+- Certain other address families (:const:`AF_BLUETOOTH`, :const:`AF_PACKET`,
+  :const:`AF_CAN`) support specific representations.
 
   .. XXX document them!
 
@@ -257,6 +257,16 @@ The module :mod:`socket` exports the following constants and functions:
 
    .. versionadded:: 3.3
 
+.. data:: CAN_BCM
+          CAN_BCM_*
+
+   CAN_BCM, in the CAN protocol family, is the broadcast manager (BCM) protocol.
+   Broadcast manager constants, documented in the Linux documentation, are also
+   defined in the socket module.
+
+   Availability: Linux >= 2.6.25.
+
+   .. versionadded:: 3.4
 
 .. data:: AF_RDS
           PF_RDS
@@ -452,13 +462,16 @@ The module :mod:`socket` exports the following constants and functions:
    :const:`AF_INET6`, :const:`AF_UNIX`, :const:`AF_CAN` or :const:`AF_RDS`. The
    socket type should be :const:`SOCK_STREAM` (the default),
    :const:`SOCK_DGRAM`, :const:`SOCK_RAW` or perhaps one of the other ``SOCK_``
-   constants. The protocol number is usually zero and may be omitted in that
-   case or :const:`CAN_RAW` in case the address family is :const:`AF_CAN`.
+   constants. The protocol number is usually zero and may be omitted or in the
+   case where the address family is :const:`AF_CAN` the protocol should be one
+   of :const:`CAN_RAW` or :const:`CAN_BCM`.
 
    .. versionchanged:: 3.3
       The AF_CAN family was added.
       The AF_RDS family was added.
 
+  .. versionchanged:: 3.4
+      The CAN_BCM protocol was added.
 
 .. function:: socketpair([family[, type[, proto]]])
 
@@ -1331,7 +1344,16 @@ the interface::
    s.ioctl(socket.SIO_RCVALL, socket.RCVALL_OFF)
 
 The last example shows how to use the socket interface to communicate to a CAN
-network. This example might require special priviledge::
+network using the raw socket protocol. To use CAN with the broadcast
+manager protocol instead, open a socket with::
+
+    socket.socket(socket.AF_CAN, socket.SOCK_DGRAM, socket.CAN_BCM)
+
+After binding (:const:`CAN_RAW`) or connecting (:const:`CAN_BCM`) the socket, you
+can use the :method:`socket.send`, and the :method:`socket.recv` operations (and
+their counterparts) on the socket object as usual.
+
+This example might require special priviledge::
 
    import socket
    import struct
diff --git a/Doc/library/ssl.rst b/Doc/library/ssl.rst
index 77196e1..40dc710 100644
--- a/Doc/library/ssl.rst
+++ b/Doc/library/ssl.rst
@@ -533,6 +533,19 @@ Constants
 
    .. versionadded:: 3.2
 
+.. data:: ALERT_DESCRIPTION_HANDSHAKE_FAILURE
+          ALERT_DESCRIPTION_INTERNAL_ERROR
+          ALERT_DESCRIPTION_*
+
+   Alert Descriptions from :rfc:`5246` and others. The `IANA TLS Alert Registry
+   <http://www.iana.org/assignments/tls-parameters/tls-parameters.xml#tls-parameters-6>`_
+   contains this list and references to the RFCs where their meaning is defined.
+
+   Used as the return value of the callback function in
+   :meth:`SSLContext.set_servername_callback`.
+
+   .. versionadded:: 3.4
+
 
 SSL Sockets
 -----------
@@ -780,6 +793,55 @@ to speed up repeated connections from the same clients.
 
    .. versionadded:: 3.3
 
+.. method:: SSLContext.set_servername_callback(server_name_callback)
+
+   Register a callback function that will be called after the TLS Client Hello
+   handshake message has been received by the SSL/TLS server when the TLS client
+   specifies a server name indication. The server name indication mechanism
+   is specified in :rfc:`6066` section 3 - Server Name Indication.
+
+   Only one callback can be set per ``SSLContext``.  If *server_name_callback*
+   is ``None`` then the callback is disabled. Calling this function a
+   subsequent time will disable the previously registered callback.
+
+   The callback function, *server_name_callback*, will be called with three
+   arguments; the first being the :class:`ssl.SSLSocket`, the second is a string
+   that represents the server name that the client is intending to communicate
+   and the third argument is the original :class:`SSLContext`. The server name
+   argument is the IDNA decoded server name.
+
+   A typical use of this callback is to change the :class:`ssl.SSLSocket`'s
+   :attr:`SSLSocket.context` attribute to a new object of type
+   :class:`SSLContext` representing a certificate chain that matches the server
+   name.
+
+   Due to the early negotiation phase of the TLS connection, only limited
+   methods and attributes are usable like
+   :meth:`SSLSocket.selected_npn_protocol` and :attr:`SSLSocket.context`.
+   :meth:`SSLSocket.getpeercert`, :meth:`SSLSocket.getpeercert`,
+   :meth:`SSLSocket.cipher` and :meth:`SSLSocket.compress` methods require that
+   the TLS connection has progressed beyond the TLS Client Hello and therefore
+   will not contain return meaningful values nor can they be called safely.
+
+   The *server_name_callback* function must return ``None`` to allow the
+   the TLS negotiation to continue.  If a TLS failure is required, a constant
+   :const:`ALERT_DESCRIPTION_* <ALERT_DESCRIPTION_INTERNAL_ERROR>` can be
+   returned.  Other return values will result in a TLS fatal error with
+   :const:`ALERT_DESCRIPTION_INTERNAL_ERROR`.
+
+   If there is a IDNA decoding error on the server name, the TLS connection
+   will terminate with an :const:`ALERT_DESCRIPTION_INTERNAL_ERROR` fatal TLS
+   alert message to the client.
+
+   If an exception is raised from the *server_name_callback* function the TLS
+   connection will terminate with a fatal TLS alert message
+   :const:`ALERT_DESCRIPTION_HANDSHAKE_FAILURE`.
+
+   This method will raise :exc:`NotImplementedError` if the OpenSSL library
+   had OPENSSL_NO_TLSEXT defined when it was built.
+
+   .. versionadded:: 3.4
+
 .. method:: SSLContext.load_dh_params(dhfile)
 
    Load the key generation parameters for Diffie-Helman (DH) key exchange.
@@ -1313,3 +1375,12 @@ use the ``openssl ciphers`` command on your system.
 
    `RFC 4366: Transport Layer Security (TLS) Extensions <http://www.ietf.org/rfc/rfc4366>`_
        Blake-Wilson et. al.
+
+   `RFC 5246: The Transport Layer Security (TLS) Protocol Version 1.2 <http://www.ietf.org/rfc/rfc5246>`_
+       T. Dierks et. al.
+
+   `RFC 6066: Transport Layer Security (TLS) Extensions <http://www.ietf.org/rfc/rfc6066>`_
+       D. Eastlake
+
+   `IANA TLS: Transport Layer Security (TLS) Parameters <http://www.iana.org/assignments/tls-parameters/tls-parameters.xml>`_
+       IANA
diff --git a/Doc/library/subprocess.rst b/Doc/library/subprocess.rst
index b09c642..cafd233 100644
--- a/Doc/library/subprocess.rst
+++ b/Doc/library/subprocess.rst
@@ -826,8 +826,6 @@ The :mod:`subprocess` module exposes the following constants.
    The new process has a new console, instead of inheriting its parent's
    console (the default).
 
-   This flag is always set when :class:`Popen` is created with ``shell=True``.
-
 .. data:: CREATE_NEW_PROCESS_GROUP
 
    A :class:`Popen` ``creationflags`` parameter to specify that a new process
diff --git a/Doc/library/sys.rst b/Doc/library/sys.rst
index 6264437..baae60e 100644
--- a/Doc/library/sys.rst
+++ b/Doc/library/sys.rst
@@ -378,6 +378,21 @@ always available.
    .. versionadded:: 3.1
 
 
+.. function:: getallocatedblocks()
+
+   Return the number of memory blocks currently allocated by the interpreter,
+   regardless of their size.  This function is mainly useful for tracking
+   and debugging memory leaks.  Because of the interpreter's internal
+   caches, the result can vary from call to call; you may have to call
+   :func:`_clear_type_cache()` and :func:`gc.collect()` to get more
+   predictable results.
+
+   If a Python build or implementation cannot reasonably compute this
+   information, :func:`getallocatedblocks()` is allowed to return 0 instead.
+
+   .. versionadded:: 3.4
+
+
 .. function:: getcheckinterval()
 
    Return the interpreter's "check interval"; see :func:`setcheckinterval`.
@@ -824,8 +839,6 @@ always available.
    Windows          ``'win32'``
    Windows/Cygwin   ``'cygwin'``
    Mac OS X         ``'darwin'``
-   OS/2             ``'os2'``
-   OS/2 EMX         ``'os2emx'``
    ================ ===========================
 
    .. versionchanged:: 3.3
@@ -1104,7 +1117,6 @@ always available.
    | :const:`name`    | Name of the thread implementation:                      |
    |                  |                                                         |
    |                  |  * ``'nt'``: Windows threads                            |
-   |                  |  * ``'os2'``: OS/2 threads                              |
    |                  |  * ``'pthread'``: POSIX threads                         |
    |                  |  * ``'solaris'``: Solaris threads                       |
    +------------------+---------------------------------------------------------+
diff --git a/Doc/library/sysconfig.rst b/Doc/library/sysconfig.rst
index c47dcce..535ac54 100644
--- a/Doc/library/sysconfig.rst
+++ b/Doc/library/sysconfig.rst
@@ -83,8 +83,6 @@ Python currently supports seven schemes:
   located under the user home directory.
 - *nt*: scheme for NT platforms like Windows.
 - *nt_user*: scheme for NT platforms, when the *user* option is used.
-- *os2*: scheme for OS/2 platforms.
-- *os2_home*: scheme for OS/2 patforms, when the *user* option is used.
 
 Each scheme is itself composed of a series of paths and each path has a unique
 identifier.  Python currently uses eight paths:
diff --git a/Doc/library/timeit.rst b/Doc/library/timeit.rst
index a487917..0cc1586 100644
--- a/Doc/library/timeit.rst
+++ b/Doc/library/timeit.rst
@@ -151,7 +151,7 @@ The module defines three convenience functions and a public class:
          t = Timer(...)       # outside the try/except
          try:
              t.timeit(...)    # or t.repeat(...)
-         except:
+         except Exception:
              t.print_exc()
 
       The advantage over the standard traceback is that source lines in the
diff --git a/Doc/library/tkinter.rst b/Doc/library/tkinter.rst
index 83a5375..377694f 100644
--- a/Doc/library/tkinter.rst
+++ b/Doc/library/tkinter.rst
@@ -750,32 +750,6 @@ Entry widget indexes (index, view index, etc.)
    displayed.  You can use these :mod:`tkinter` functions to access these special
    points in text widgets:
 
-.. function:: AtEnd()
-      refers to the last position in the text
-
-   .. deprecated:: 3.3
-
-.. function:: AtInsert()
-      refers to the point where the text cursor is
-
-   .. deprecated:: 3.3
-
-.. function:: AtSelFirst()
-      indicates the beginning point of the selected text
-
-   .. deprecated:: 3.3
-
-.. function:: AtSelLast()
-      denotes the last point of the selected text and finally
-
-   .. deprecated:: 3.3
-
-.. function:: At(x[, y])
-      refers to the character at pixel location *x*, *y* (with *y* not used in the
-      case of a text entry widget, which contains a single line of text).
-
-   .. deprecated:: 3.3
-
 Text widget indexes
    The index notation for Text widgets is very rich and is best described in the Tk
    man pages.
diff --git a/Doc/library/traceback.rst b/Doc/library/traceback.rst
index 32e5733..0533bea 100644
--- a/Doc/library/traceback.rst
+++ b/Doc/library/traceback.rst
@@ -146,7 +146,7 @@ module. ::
        source = input(">>> ")
        try:
            exec(source, envdir)
-       except:
+       except Exception:
            print("Exception in user code:")
            print("-"*60)
            traceback.print_exc(file=sys.stdout)
diff --git a/Doc/library/unicodedata.rst b/Doc/library/unicodedata.rst
index ad70dd9..52acc18 100644
--- a/Doc/library/unicodedata.rst
+++ b/Doc/library/unicodedata.rst
@@ -15,8 +15,8 @@
 
 This module provides access to the Unicode Character Database (UCD) which
 defines character properties for all Unicode characters. The data contained in
-this database is compiled from the `UCD version 6.1.0
-<http://www.unicode.org/Public/6.1.0/ucd>`_.
+this database is compiled from the `UCD version 6.2.0
+<http://www.unicode.org/Public/6.2.0/ucd>`_.
 
 The module uses the same names and symbols as defined by Unicode
 Standard Annex #44, `"Unicode Character Database"
diff --git a/Doc/library/unittest.mock-examples.rst b/Doc/library/unittest.mock-examples.rst
index 94fd1404..cbdba1d 100644
--- a/Doc/library/unittest.mock-examples.rst
+++ b/Doc/library/unittest.mock-examples.rst
@@ -277,6 +277,20 @@ instantiate the class in those tests.
        ...
     AttributeError: object has no attribute 'old_method'
 
+Using a specification also enables a smarter matching of calls made to the
+mock, regardless of whether some parameters were passed as positional or
+named arguments::
+
+   >>> def f(a, b, c): pass
+   ...
+   >>> mock = Mock(spec=f)
+   >>> mock(1, 2, 3)
+   <Mock name='mock()' id='140161580456576'>
+   >>> mock.assert_called_with(a=1, b=2, c=3)
+
+If you want this smarter matching to also work with method calls on the mock,
+you can use :ref:`auto-speccing <auto-speccing>`.
+
 If you want a stronger form of specification that prevents the setting
 of arbitrary attributes as well as the getting of them then you can use
 `spec_set` instead of `spec`.
diff --git a/Doc/library/unittest.mock.rst b/Doc/library/unittest.mock.rst
index 97e595d..1b8f6b4 100644
--- a/Doc/library/unittest.mock.rst
+++ b/Doc/library/unittest.mock.rst
@@ -264,7 +264,6 @@ the `new_callable` argument to `patch`.
             <Mock name='mock.method()' id='...'>
             >>> mock.method.assert_called_with(1, 2, 3, test='wow')
 
-
     .. method:: assert_called_once_with(*args, **kwargs)
 
        Assert that the mock was called exactly once and with the specified
@@ -685,6 +684,27 @@ have to create a dictionary and unpack it using `**`:
       ...
     KeyError
 
+A callable mock which was created with a *spec* (or a *spec_set*) will
+introspect the specification object's signature when matching calls to
+the mock.  Therefore, it can match the actual call's arguments regardless
+of whether they were passed positionally or by name::
+
+   >>> def f(a, b, c): pass
+   ...
+   >>> mock = Mock(spec=f)
+   >>> mock(1, 2, c=3)
+   <Mock name='mock()' id='140161580456576'>
+   >>> mock.assert_called_with(1, 2, 3)
+   >>> mock.assert_called_with(a=1, b=2, c=3)
+
+This applies to :meth:`~Mock.assert_called_with`,
+:meth:`~Mock.assert_called_once_with`, :meth:`~Mock.assert_has_calls` and
+:meth:`~Mock.assert_any_call`.  When :ref:`auto-speccing`, it will also
+apply to method calls on the mock object.
+
+   .. versionchanged:: 3.4
+      Added signature introspection on specced and autospecced mock objects.
+
 
 .. class:: PropertyMock(*args, **kwargs)
 
diff --git a/Doc/library/urllib.error.rst b/Doc/library/urllib.error.rst
index 9c3fe91..7bd04b1 100644
--- a/Doc/library/urllib.error.rst
+++ b/Doc/library/urllib.error.rst
@@ -45,6 +45,13 @@ The following exceptions are raised by :mod:`urllib.error` as appropriate:
 
       This is usually a string explaining the reason for this error.
 
+   .. attribute:: headers
+
+      The HTTP response headers for the HTTP request that cause the
+      :exc:`HTTPError`.
+
+      .. versionadded:: 3.4
+
 .. exception:: ContentTooShortError(msg, content)
 
    This exception is raised when the :func:`urlretrieve` function detects that
diff --git a/Doc/library/urllib.request.rst b/Doc/library/urllib.request.rst
index 21255e5..d5f3f2c 100644
--- a/Doc/library/urllib.request.rst
+++ b/Doc/library/urllib.request.rst
@@ -121,7 +121,7 @@ The :mod:`urllib.request` module defines the following functions:
    instances of them or subclasses of them: :class:`ProxyHandler`,
    :class:`UnknownHandler`, :class:`HTTPHandler`, :class:`HTTPDefaultErrorHandler`,
    :class:`HTTPRedirectHandler`, :class:`FTPHandler`, :class:`FileHandler`,
-   :class:`HTTPErrorProcessor`.
+   :class:`HTTPErrorProcessor`, :class:`DataHandler`.
 
    If the Python installation has SSL support (i.e., if the :mod:`ssl` module
    can be imported), :class:`HTTPSHandler` will also be added.
@@ -346,6 +346,11 @@ The following classes are provided:
 
    Open local files.
 
+.. class:: DataHandler()
+
+   Open data URLs.
+
+   .. versionadded:: 3.4
 
 .. class:: FTPHandler()
 
@@ -403,6 +408,10 @@ request.
 
    The entity body for the request, or None if not specified.
 
+   .. versionchanged:: 3.4
+      Changing value of :attr:`Request.data` now deletes "Content-Length"
+      header if it was previously set or calculated.
+
 .. attribute:: Request.unverifiable
 
    boolean, indicates whether the request is unverifiable as defined
@@ -451,6 +460,14 @@ request.
    unredirected).
 
 
+.. method:: Request.remove_header(header)
+
+   Remove named header from the request instance (both from regular and
+   unredirected headers).
+
+   .. versionadded:: 3.4
+
+
 .. method:: Request.get_full_url()
 
    Return the URL given in the constructor.
@@ -972,6 +989,21 @@ FileHandler Objects
       hostname is given, an :exc:`URLError` is raised.
 
 
+.. _data-handler-objects:
+
+DataHandler Objects
+-------------------
+
+.. method:: DataHandler.data_open(req)
+
+   Read a data URL. This kind of URL contains the content encoded in the URL
+   itself. The data URL syntax is specified in :rfc:`2397`. This implementation
+   ignores white spaces in base64 encoded data URLs so the URL may be wrapped
+   in whatever source file it comes from. But even though some browsers don't
+   mind about a missing padding at the end of a base64 encoded data URL, this
+   implementation will raise an :exc:`ValueError` in that case.
+
+
 .. _ftp-handler-objects:
 
 FTPHandler Objects
@@ -1374,7 +1406,9 @@ some point in the future.
      pair: FTP; protocol
 
 * Currently, only the following protocols are supported: HTTP (versions 0.9 and
-  1.0), FTP, and local files.
+  1.0), FTP, local files, and data URLs.
+
+  .. versionchanged:: 3.4 Added support for data URLs.
 
 * The caching feature of :func:`urlretrieve` has been disabled until someone
   finds the time to hack proper processing of Expiration time headers.
diff --git a/Doc/library/venv.rst b/Doc/library/venv.rst
index cd04808..5cd209c 100644
--- a/Doc/library/venv.rst
+++ b/Doc/library/venv.rst
@@ -75,8 +75,8 @@ creation according to their needs, the :class:`EnvBuilder` class.
     * ``system_site_packages`` -- a Boolean value indicating that the system Python
       site-packages should be available to the environment (defaults to ``False``).
 
-    * ``clear`` -- a Boolean value which, if True, will delete any existing target
-      directory instead of raising an exception (defaults to ``False``).
+    * ``clear`` -- a Boolean value which, if True, will delete the contents of
+      any existing target directory, before creating the environment.
 
     * ``symlinks`` -- a Boolean value indicating whether to attempt to symlink the
       Python binary (and any necessary DLLs or other binaries,
@@ -88,7 +88,6 @@ creation according to their needs, the :class:`EnvBuilder` class.
       upgraded in-place (defaults to ``False``).
 
 
-
     Creators of third-party virtual environment tools will be free to use the
     provided ``EnvBuilder`` class as a base class.
 
diff --git a/Doc/library/weakref.rst b/Doc/library/weakref.rst
index 224f442..1bf6b58 100644
--- a/Doc/library/weakref.rst
+++ b/Doc/library/weakref.rst
@@ -192,6 +192,35 @@ These method have the same issues as the and :meth:`keyrefs` method of
    discarded when no strong reference to it exists any more.
 
 
+.. class:: WeakMethod(method)
+
+   A custom :class:`ref` subclass which simulates a weak reference to a bound
+   method (i.e., a method defined on a class and looked up on an instance).
+   Since a bound method is ephemeral, a standard weak reference cannot keep
+   hold of it.  :class:`WeakMethod` has special code to recreate the bound
+   method until either the object or the original function dies::
+
+      >>> class C:
+      ...     def method(self):
+      ...         print("method called!")
+      ...
+      >>> c = C()
+      >>> r = weakref.ref(c.method)
+      >>> r()
+      >>> r = weakref.WeakMethod(c.method)
+      >>> r()
+      <bound method C.method of <__main__.C object at 0x7fc859830220>>
+      >>> r()()
+      method called!
+      >>> del c
+      >>> gc.collect()
+      0
+      >>> r()
+      >>>
+
+   .. versionadded:: 3.4
+
+
 .. data:: ReferenceType
 
    The type object for weak references objects.
diff --git a/Doc/library/xml.etree.elementtree.rst b/Doc/library/xml.etree.elementtree.rst
index 144e344..2a9f9b3 100644
--- a/Doc/library/xml.etree.elementtree.rst
+++ b/Doc/library/xml.etree.elementtree.rst
@@ -428,29 +428,39 @@ Functions
    arguments.  Returns an element instance.
 
 
-.. function:: tostring(element, encoding="us-ascii", method="xml")
+.. function:: tostring(element, encoding="us-ascii", method="xml", *, \
+                       short_empty_elements=True)
 
    Generates a string representation of an XML element, including all
    subelements.  *element* is an :class:`Element` instance.  *encoding* [1]_ is
    the output encoding (default is US-ASCII).  Use ``encoding="unicode"`` to
    generate a Unicode string (otherwise, a bytestring is generated).  *method*
    is either ``"xml"``, ``"html"`` or ``"text"`` (default is ``"xml"``).
+   *short_empty_elements* has the same meaning as in :meth:`ElementTree.write`.
    Returns an (optionally) encoded string containing the XML data.
 
+   .. versionadded:: 3.4
+      The *short_empty_elements* parameter.
 
-.. function:: tostringlist(element, encoding="us-ascii", method="xml")
+
+.. function:: tostringlist(element, encoding="us-ascii", method="xml", *, \
+                           short_empty_elements=True)
 
    Generates a string representation of an XML element, including all
    subelements.  *element* is an :class:`Element` instance.  *encoding* [1]_ is
    the output encoding (default is US-ASCII).  Use ``encoding="unicode"`` to
    generate a Unicode string (otherwise, a bytestring is generated).  *method*
    is either ``"xml"``, ``"html"`` or ``"text"`` (default is ``"xml"``).
+   *short_empty_elements* has the same meaning as in :meth:`ElementTree.write`.
    Returns a list of (optionally) encoded strings containing the XML data.
    It does not guarantee any specific sequence, except that
    ``"".join(tostringlist(element)) == tostring(element)``.
 
    .. versionadded:: 3.2
 
+   .. versionadded:: 3.4
+      The *short_empty_elements* parameter.
+
 
 .. function:: XML(text, parser=None)
 
@@ -742,7 +752,8 @@ ElementTree Objects
 
 
    .. method:: write(file, encoding="us-ascii", xml_declaration=None, \
-                     default_namespace=None, method="xml")
+                     default_namespace=None, method="xml", *, \
+                     short_empty_elements=True)
 
       Writes the element tree to a file, as XML.  *file* is a file name, or a
       :term:`file object` opened for writing.  *encoding* [1]_ is the output
@@ -753,6 +764,10 @@ ElementTree Objects
       *default_namespace* sets the default XML namespace (for "xmlns").
       *method* is either ``"xml"``, ``"html"`` or ``"text"`` (default is
       ``"xml"``).
+      The keyword-only *short_empty_elements* parameter controls the formatting
+      of elements that contain no content.  If *True* (the default), they are
+      emitted as a single self-closed tag, otherwise they are emitted as a pair
+      of start/end tags.
 
       The output is either a string (:class:`str`) or binary (:class:`bytes`).
       This is controlled by the *encoding* argument.  If *encoding* is
@@ -761,6 +776,9 @@ ElementTree Objects
       :term:`file object`; make sure you do not try to write a string to a
       binary stream and vice versa.
 
+   .. versionadded:: 3.4
+      The *short_empty_elements* parameter.
+
 
 This is the XML file that is going to be manipulated::
 
diff --git a/Doc/license.rst b/Doc/license.rst
index 5b7fcbd..3508d54 100644
--- a/Doc/license.rst
+++ b/Doc/license.rst
@@ -122,6 +122,8 @@ been GPL-compatible; the table below summarizes the various releases.
 +----------------+--------------+------------+------------+-----------------+
 | 3.3.0          | 3.2          | 2012       | PSF        | yes             |
 +----------------+--------------+------------+------------+-----------------+
+| 3.4.0          | 3.3.0        | 2014       | PSF        | yes             |
++----------------+--------------+------------+------------+-----------------+
 
 .. note::
 
@@ -656,6 +658,25 @@ The :mod:`select` and contains the following notice for the kqueue interface::
   SUCH DAMAGE.
 
 
+SHA-3
+-----
+
+The module :mod:`_sha3` and :mod:`hashlib` are using the reference
+implementation of Keccak. The files at :file:`Modules/_sha3/keccak/` contain
+the following note::
+
+  The Keccak sponge function, designed by Guido Bertoni, Joan Daemen,
+  Michaël Peeters and Gilles Van Assche. For more information, feedback or
+  questions, please refer to our website: http://keccak.noekeon.org/
+
+  Implementation by the designers,
+  hereby denoted as "the implementer".
+
+  To the extent possible under law, the implementer has waived all copyright
+  and related or neighboring rights to the source code in this file.
+  http://creativecommons.org/publicdomain/zero/1.0/
+
+
 strtod and dtoa
 ---------------
 
diff --git a/Doc/reference/datamodel.rst b/Doc/reference/datamodel.rst
index 7c51068..9a39eb4 100644
--- a/Doc/reference/datamodel.rst
+++ b/Doc/reference/datamodel.rst
@@ -1815,6 +1815,15 @@ through the container; for mappings, :meth:`__iter__` should be the same as
    considered to be false in a Boolean context.
 
 
+.. method:: object.__length_hint__(self)
+
+   Called to implement :func:`operator.length_hint`. Should return an estimated
+   length for the object (which may be greater or less than the actual length).
+   The length must be an integer ``>=`` 0. This method is purely an
+   optimization and is never required for correctness.
+
+   .. versionadded:: 3.4
+
 .. note::
 
    Slicing is done exclusively with the following three methods.  A call like ::
diff --git a/Doc/tools/sphinxext/indexsidebar.html b/Doc/tools/sphinxext/indexsidebar.html
index a0ec32f..ed5da0c 100644
--- a/Doc/tools/sphinxext/indexsidebar.html
+++ b/Doc/tools/sphinxext/indexsidebar.html
@@ -3,7 +3,7 @@
 	    <h3>Docs for other versions</h3>
 	    <ul>
 	      <li><a href="http://docs.python.org/2.7/">Python 2.7 (stable)</a></li>
-	      <li><a href="http://docs.python.org/3.4/">Python 3.4 (in development)</a></li>
+	      <li><a href="http://docs.python.org/3.3/">Python 3.3 (stable)</a></li>
               <li><a href="http://www.python.org/doc/versions/">Old versions</a></li>
             </ul>
 
diff --git a/Doc/tools/sphinxext/pyspecific.py b/Doc/tools/sphinxext/pyspecific.py
index e8eb703..df6e48a 100644
--- a/Doc/tools/sphinxext/pyspecific.py
+++ b/Doc/tools/sphinxext/pyspecific.py
@@ -10,7 +10,7 @@
 """
 
 ISSUE_URI = 'http://bugs.python.org/issue%s'
-SOURCE_URI = 'http://hg.python.org/cpython/file/3.3/%s'
+SOURCE_URI = 'http://hg.python.org/cpython/file/default/%s'
 
 from docutils import nodes, utils
 from sphinx.util.nodes import split_explicit_title
diff --git a/Doc/tutorial/interpreter.rst b/Doc/tutorial/interpreter.rst
index cdc2bf2..c182511 100644
--- a/Doc/tutorial/interpreter.rst
+++ b/Doc/tutorial/interpreter.rst
@@ -10,13 +10,13 @@ Using the Python Interpreter
 Invoking the Interpreter
 ========================
 
-The Python interpreter is usually installed as :file:`/usr/local/bin/python3.3`
+The Python interpreter is usually installed as :file:`/usr/local/bin/python3.4`
 on those machines where it is available; putting :file:`/usr/local/bin` in your
 Unix shell's search path makes it possible to start it by typing the command:
 
 .. code-block:: text
 
-   python3.3
+   python3.4
 
 to the shell. [#]_ Since the choice of the directory where the interpreter lives
 is an installation option, other places are possible; check with your local
@@ -24,11 +24,11 @@ Python guru or system administrator.  (E.g., :file:`/usr/local/python` is a
 popular alternative location.)
 
 On Windows machines, the Python installation is usually placed in
-:file:`C:\\Python33`, though you can change this when you're running the
+:file:`C:\\Python34`, though you can change this when you're running the
 installer.  To add this directory to your path,  you can type the following
 command into the command prompt in a DOS box::
 
-   set path=%path%;C:\python33
+   set path=%path%;C:\python34
 
 Typing an end-of-file character (:kbd:`Control-D` on Unix, :kbd:`Control-Z` on
 Windows) at the primary prompt causes the interpreter to exit with a zero exit
@@ -95,8 +95,8 @@ with the *secondary prompt*, by default three dots (``...``). The interpreter
 prints a welcome message stating its version number and a copyright notice
 before printing the first prompt::
 
-   $ python3.3
-   Python 3.3 (default, Sep 24 2012, 09:25:04)
+   $ python3.4
+   Python 3.4 (default, Sep 24 2012, 09:25:04)
    [GCC 4.6.3] on linux2
    Type "help", "copyright", "credits" or "license" for more information.
    >>>
@@ -149,7 +149,7 @@ Executable Python Scripts
 On BSD'ish Unix systems, Python scripts can be made directly executable, like
 shell scripts, by putting the line ::
 
-   #! /usr/bin/env python3.3
+   #! /usr/bin/env python3.4
 
 (assuming that the interpreter is on the user's :envvar:`PATH`) at the beginning
 of the script and giving the file an executable mode.  The ``#!`` must be the
diff --git a/Doc/tutorial/modules.rst b/Doc/tutorial/modules.rst
index c4d86ac..3a3283d 100644
--- a/Doc/tutorial/modules.rst
+++ b/Doc/tutorial/modules.rst
@@ -289,24 +289,23 @@ defines.  It returns a sorted list of strings::
    >>> dir(fibo)
    ['__name__', 'fib', 'fib2']
    >>> dir(sys)  # doctest: +NORMALIZE_WHITESPACE
-   ['__displayhook__', '__doc__', '__egginsert', '__excepthook__',
-    '__loader__', '__name__', '__package__', '__plen', '__stderr__',
-    '__stdin__', '__stdout__', '_clear_type_cache', '_current_frames',
-    '_debugmallocstats', '_getframe', '_home', '_mercurial', '_xoptions',
-    'abiflags', 'api_version', 'argv', 'base_exec_prefix', 'base_prefix',
-    'builtin_module_names', 'byteorder', 'call_tracing', 'callstats',
-    'copyright', 'displayhook', 'dont_write_bytecode', 'exc_info',
-    'excepthook', 'exec_prefix', 'executable', 'exit', 'flags', 'float_info',
-    'float_repr_style', 'getcheckinterval', 'getdefaultencoding',
-    'getdlopenflags', 'getfilesystemencoding', 'getobjects', 'getprofile',
-    'getrecursionlimit', 'getrefcount', 'getsizeof', 'getswitchinterval',
-    'gettotalrefcount', 'gettrace', 'hash_info', 'hexversion',
-    'implementation', 'int_info', 'intern', 'maxsize', 'maxunicode',
-    'meta_path', 'modules', 'path', 'path_hooks', 'path_importer_cache',
-    'platform', 'prefix', 'ps1', 'setcheckinterval', 'setdlopenflags',
-    'setprofile', 'setrecursionlimit', 'setswitchinterval', 'settrace',
-    'stderr', 'stdin', 'stdout', 'thread_info', 'version', 'version_info',
-    'warnoptions']
+   ['__displayhook__', '__doc__', '__excepthook__', '__loader__', '__name__',
+    '__package__', '__stderr__', '__stdin__', '__stdout__',
+    '_clear_type_cache', '_current_frames', '_debugmallocstats', '_getframe',
+    '_home', '_mercurial', '_xoptions', 'abiflags', 'api_version', 'argv',
+    'base_exec_prefix', 'base_prefix', 'builtin_module_names', 'byteorder',
+    'call_tracing', 'callstats', 'copyright', 'displayhook',
+    'dont_write_bytecode', 'exc_info', 'excepthook', 'exec_prefix',
+    'executable', 'exit', 'flags', 'float_info', 'float_repr_style',
+    'getcheckinterval', 'getdefaultencoding', 'getdlopenflags',
+    'getfilesystemencoding', 'getobjects', 'getprofile', 'getrecursionlimit',
+    'getrefcount', 'getsizeof', 'getswitchinterval', 'gettotalrefcount',
+    'gettrace', 'hash_info', 'hexversion', 'implementation', 'int_info',
+    'intern', 'maxsize', 'maxunicode', 'meta_path', 'modules', 'path',
+    'path_hooks', 'path_importer_cache', 'platform', 'prefix', 'ps1',
+    'setcheckinterval', 'setdlopenflags', 'setprofile', 'setrecursionlimit',
+    'setswitchinterval', 'settrace', 'stderr', 'stdin', 'stdout',
+    'thread_info', 'version', 'version_info', 'warnoptions']
 
 Without arguments, :func:`dir` lists the names you have defined currently::
 
diff --git a/Doc/tutorial/stdlib.rst b/Doc/tutorial/stdlib.rst
index 1ebf792..cb892fd 100644
--- a/Doc/tutorial/stdlib.rst
+++ b/Doc/tutorial/stdlib.rst
@@ -15,7 +15,7 @@ operating system::
 
    >>> import os
    >>> os.getcwd()      # Return the current working directory
-   'C:\\Python33'
+   'C:\\Python34'
    >>> os.chdir('/server/accesslogs')   # Change current working directory
    >>> os.system('mkdir today')   # Run the command mkdir in the system shell
    0
diff --git a/Doc/tutorial/stdlib2.rst b/Doc/tutorial/stdlib2.rst
index 4b6e036..3b9122f 100644
--- a/Doc/tutorial/stdlib2.rst
+++ b/Doc/tutorial/stdlib2.rst
@@ -275,7 +275,7 @@ applications include caching objects that are expensive to create::
    Traceback (most recent call last):
      File "<stdin>", line 1, in <module>
        d['primary']                # entry was automatically removed
-     File "C:/python33/lib/weakref.py", line 46, in __getitem__
+     File "C:/python34/lib/weakref.py", line 46, in __getitem__
        o = self.data[key]()
    KeyError: 'primary'
 
diff --git a/Doc/using/venv-create.inc b/Doc/using/venv-create.inc
index 5fdbc9b..706ac5d 100644
--- a/Doc/using/venv-create.inc
+++ b/Doc/using/venv-create.inc
@@ -56,20 +56,21 @@ virtualenv will be created, according to the given options, at each
 provided path.
 
 Once a venv has been created, it can be "activated" using a script in the
-venv's binary directory. The invocation of the script is platform-specific: on
-a Posix platform, you would typically do::
-
-    $ source <venv>/bin/activate
-
-whereas on Windows, you might do::
-
-    C:\> <venv>/Scripts/activate
-
-if you are using the ``cmd.exe`` shell, or perhaps::
-
-    PS C:\> <venv>/Scripts/Activate.ps1
-
-if you use PowerShell.
+venv's binary directory. The invocation of the script is platform-specific:
+
++-------------+-----------------+-----------------------------------------+
+| Platform    | Shell           | Command to activate virtual environment |
++=============+=================+=========================================+
+| Posix       | bash/zsh        | $ source <venv>/bin/activate            |
++-------------+-----------------+-----------------------------------------+
+|             | fish            | $ . <venv>/bin/activate.fish            |
++-------------+-----------------+-----------------------------------------+
+|             | csh/tcsh        | $ source <venv>/bin/activate.csh        |
++-------------+-----------------+-----------------------------------------+
+| Windows     | cmd.exe         | C:\> <venv>/Scripts/activate.bat        |
++-------------+-----------------+-----------------------------------------+
+|             | PowerShell      | PS C:\> <venv>/Scripts/Activate.ps1     |
++-------------+-----------------+-----------------------------------------+
 
 You don't specifically *need* to activate an environment; activation just
 prepends the venv's binary directory to your path, so that "python" invokes the
diff --git a/Doc/whatsnew/3.4.rst b/Doc/whatsnew/3.4.rst
new file mode 100644
index 0000000..ab0b163
--- /dev/null
+++ b/Doc/whatsnew/3.4.rst
@@ -0,0 +1,209 @@
+****************************
+  What's New In Python 3.4
+****************************
+
+.. :Author: Someone <email>
+   (uncomment if there is a principal author)
+
+.. Rules for maintenance:
+
+   * Anyone can add text to this document, but the maintainer reserves the
+   right to rewrite any additions. In particular, for obscure or esoteric
+   features, the maintainer may reduce any addition to a simple reference to
+   the new documentation rather than explaining the feature inline.
+
+   * While the maintainer will periodically go through Misc/NEWS
+   and add changes, it's best not to rely on this. We know from experience
+   that any changes that aren't in the What's New documentation around the
+   time of the original release will remain largely unknown to the community
+   for years, even if they're added later. We also know from experience that
+   other priorities can arise, and the maintainer will run out of time to do
+   updates - in such cases, end users will be much better served by partial
+   notifications that at least give a hint about new features to
+   investigate.
+
+   * This is not a complete list of every single change; completeness
+   is the purpose of Misc/NEWS. The What's New should focus on changes that
+   are visible to Python *users* and that *require* a feature release (i.e.
+   most bug fixes should only be recorded in Misc/NEWS)
+
+   * PEPs should not be marked Final until they have an entry in What's New.
+   A placeholder entry that is just a section header and a link to the PEP
+   (e.g ":pep:`397` has been implemented") is acceptable. If a PEP has been
+   implemented and noted in What's New, don't forget to mark it as Final!
+
+   * If you want to draw your new text to the attention of the
+   maintainer, add 'XXX' to the beginning of the paragraph or
+   section.
+
+   * It's OK to add just a very brief note about a change.  For
+   example: "The :ref:`~socket.transmogrify()` function was added to the
+   :mod:`socket` module."  The maintainer will research the change and
+   write the necessary text (if appropriate). The advantage of doing this
+   is that even if no more descriptive text is ever added, readers will at
+   least have a notification that the new feature exists and a link to the
+   relevant documentation.
+
+   * You can comment out your additions if you like, but it's not
+   necessary (especially when a final release is some months away).
+
+   * Credit the author of a patch or bugfix.   Just the name is
+   sufficient; the e-mail address isn't necessary.
+
+   * It's helpful to add the bug/patch number as a comment:
+
+   The :ref:`~socket.transmogrify()` function was added to the
+   :mod:`socket` module. (Contributed by P.Y. Developer in :issue:`12345`.)
+
+   This saves the maintainer the effort of going through the Mercurial log
+   when researching a change.
+
+   * Cross referencing tip: :ref:`mod.attr` will display as ``mod.attr``,
+   while :ref:`~mod.attr` will display as ``attr``.
+
+This article explains the new features in Python 3.4, compared to 3.3.
+
+.. Python 3.4 was released on TBD.
+
+For full details, see the
+`changelog <http://docs.python.org/3.4/whatsnew/changelog.html>`_.
+
+.. note:: Prerelease users should be aware that this document is currently in
+   draft form. It will be updated substantially as Python 3.4 moves towards
+   release, so it's worth checking back even after reading earlier versions.
+
+
+.. seealso::
+
+   .. :pep:`4XX` - Python 3.4 Release Schedule
+
+
+Summary -- Release highlights
+=============================
+
+.. This section singles out the most important changes in Python 3.3.
+   Brevity is key.
+
+New syntax features:
+
+* None yet.
+
+New library modules:
+
+* None yet.
+
+New built-in features:
+
+* None yet.
+
+Implementation improvements:
+
+* None yet.
+
+Significantly Improved Library Modules:
+
+* SHA-3 (Keccak) support for :mod:`hashlib`.
+
+Security improvements:
+
+* None yet.
+
+Please read on for a comprehensive list of user-facing changes.
+
+
+.. PEP-sized items next.
+
+.. _pep-4XX:
+
+.. PEP 4XX: Example PEP
+.. ====================
+
+
+.. (Implemented by Foo Bar.)
+
+.. .. seealso::
+
+   :pep:`4XX` - Example PEP
+      PEP written by Example Author
+
+
+
+
+Other Language Changes
+======================
+
+Some smaller changes made to the core Python language are:
+
+* Unicode database updated to UCD version 6.2.
+
+
+
+New Modules
+===========
+
+.. module name
+.. -----------
+
+* None yet.
+
+
+Improved Modules
+================
+
+doctest
+-------
+
+Added ``FAIL_FAST`` flag to halt test running as soon as the first failure is
+detected.  (Contributed by R. David Murray and Daniel Urban in :issue:`16522`.)
+
+
+Optimizations
+=============
+
+Major performance enhancements have been added:
+
+* The UTF-32 decoder is now 3x to 4x faster.
+
+
+Build and C API Changes
+=======================
+
+Changes to Python's build process and to the C API include:
+
+* None yet.
+
+
+Deprecated
+==========
+
+Unsupported Operating Systems
+-----------------------------
+
+* None yet.
+
+
+Deprecated Python modules, functions and methods
+------------------------------------------------
+
+* None yet.
+
+
+Deprecated functions and types of the C API
+-------------------------------------------
+
+* None yet.
+
+
+Deprecated features
+-------------------
+
+* None yet.
+
+
+Porting to Python 3.4
+=====================
+
+This section lists previously described changes and other bugfixes
+that may require changes to your code.
+
+* Nothing yet.
diff --git a/Doc/whatsnew/index.rst b/Doc/whatsnew/index.rst
index bc1206b..29902e4 100644
--- a/Doc/whatsnew/index.rst
+++ b/Doc/whatsnew/index.rst
@@ -11,6 +11,7 @@ anyone wishing to stay up-to-date after a new release.
 .. toctree::
    :maxdepth: 2
 
+   3.4.rst
    3.3.rst
    3.2.rst
    3.1.rst
diff --git a/Include/Python-ast.h b/Include/Python-ast.h
index 7ad6cb3..9d88d5d 100644
--- a/Include/Python-ast.h
+++ b/Include/Python-ast.h
@@ -182,8 +182,9 @@ enum _expr_kind {BoolOp_kind=1, BinOp_kind=2, UnaryOp_kind=3, Lambda_kind=4,
                   SetComp_kind=9, DictComp_kind=10, GeneratorExp_kind=11,
                   Yield_kind=12, YieldFrom_kind=13, Compare_kind=14,
                   Call_kind=15, Num_kind=16, Str_kind=17, Bytes_kind=18,
-                  Ellipsis_kind=19, Attribute_kind=20, Subscript_kind=21,
-                  Starred_kind=22, Name_kind=23, List_kind=24, Tuple_kind=25};
+                  NameConstant_kind=19, Ellipsis_kind=20, Attribute_kind=21,
+                  Subscript_kind=22, Starred_kind=23, Name_kind=24,
+                  List_kind=25, Tuple_kind=26};
 struct _expr {
         enum _expr_kind kind;
         union {
@@ -279,6 +280,10 @@ struct _expr {
                 } Bytes;
                 
                 struct {
+                        singleton value;
+                } NameConstant;
+                
+                struct {
                         expr_ty value;
                         identifier attr;
                         expr_context_ty ctx;
@@ -509,6 +514,9 @@ expr_ty _Py_Num(object n, int lineno, int col_offset, PyArena *arena);
 expr_ty _Py_Str(string s, int lineno, int col_offset, PyArena *arena);
 #define Bytes(a0, a1, a2, a3) _Py_Bytes(a0, a1, a2, a3)
 expr_ty _Py_Bytes(bytes s, int lineno, int col_offset, PyArena *arena);
+#define NameConstant(a0, a1, a2, a3) _Py_NameConstant(a0, a1, a2, a3)
+expr_ty _Py_NameConstant(singleton value, int lineno, int col_offset, PyArena
+                         *arena);
 #define Ellipsis(a0, a1, a2) _Py_Ellipsis(a0, a1, a2)
 expr_ty _Py_Ellipsis(int lineno, int col_offset, PyArena *arena);
 #define Attribute(a0, a1, a2, a3, a4, a5) _Py_Attribute(a0, a1, a2, a3, a4, a5)
diff --git a/Include/abstract.h b/Include/abstract.h
index 44b5af7..e2b0750 100644
--- a/Include/abstract.h
+++ b/Include/abstract.h
@@ -404,8 +404,9 @@ xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx*/
 #define PyObject_Length PyObject_Size
 
 #ifndef Py_LIMITED_API
-     PyAPI_FUNC(Py_ssize_t) _PyObject_LengthHint(PyObject *o, Py_ssize_t);
+     PyAPI_FUNC(int) _PyObject_HasLen(PyObject *o);
 #endif
+PyAPI_FUNC(Py_ssize_t) PyObject_LengthHint(PyObject *o, Py_ssize_t);
 
        /*
      Guess the size of object o using len(o) or o.__length_hint__().
diff --git a/Include/asdl.h b/Include/asdl.h
index 6bf618f..0789ad8 100644
--- a/Include/asdl.h
+++ b/Include/asdl.h
@@ -5,6 +5,7 @@ typedef PyObject * identifier;
 typedef PyObject * string;
 typedef PyObject * bytes;
 typedef PyObject * object;
+typedef PyObject * singleton;
 
 /* It would be nice if the code generated by asdl_c.py was completely
    independent of Python, but it is a goal the requires too much work
diff --git a/Include/grammar.h b/Include/grammar.h
index 8426da3..862f6a8 100644
--- a/Include/grammar.h
+++ b/Include/grammar.h
@@ -76,7 +76,7 @@ dfa *PyGrammar_FindDFA(grammar *g, int type);
 
 int addlabel(labellist *ll, int type, char *str);
 int findlabel(labellist *ll, int type, char *str);
-char *PyGrammar_LabelRepr(label *lb);
+const char *PyGrammar_LabelRepr(label *lb);
 void translatelabels(grammar *g);
 
 void addfirstsets(grammar *g);
diff --git a/Include/object.h b/Include/object.h
index 387cadb..ad58450 100644
--- a/Include/object.h
+++ b/Include/object.h
@@ -362,7 +362,7 @@ typedef struct _typeobject {
     PyBufferProcs *tp_as_buffer;
 
     /* Flags to define presence of optional/expanded features */
-    long tp_flags;
+    unsigned long tp_flags;
 
     const char *tp_doc; /* Documentation string */
 
@@ -428,7 +428,7 @@ typedef struct{
     const char* name;
     int basicsize;
     int itemsize;
-    int flags;
+    unsigned int flags;
     PyType_Slot *slots; /* terminated by slot==0. */
 } PyType_Spec;
 
@@ -470,7 +470,7 @@ PyAPI_DATA(PyTypeObject) PyType_Type; /* built-in 'type' */
 PyAPI_DATA(PyTypeObject) PyBaseObject_Type; /* built-in 'object' */
 PyAPI_DATA(PyTypeObject) PySuper_Type; /* built-in 'super' */
 
-PyAPI_FUNC(long) PyType_GetFlags(PyTypeObject*);
+PyAPI_FUNC(unsigned long) PyType_GetFlags(PyTypeObject*);
 
 #define PyType_Check(op) \
     PyType_FastSubclass(Py_TYPE(op), Py_TPFLAGS_TYPE_SUBCLASS)
@@ -603,44 +603,43 @@ given type object has a specified feature.
 */
 
 /* Set if the type object is dynamically allocated */
-#define Py_TPFLAGS_HEAPTYPE (1L<<9)
+#define Py_TPFLAGS_HEAPTYPE (1UL << 9)
 
 /* Set if the type allows subclassing */
-#define Py_TPFLAGS_BASETYPE (1L<<10)
+#define Py_TPFLAGS_BASETYPE (1UL << 10)
 
 /* Set if the type is 'ready' -- fully initialized */
-#define Py_TPFLAGS_READY (1L<<12)
+#define Py_TPFLAGS_READY (1UL << 12)
 
 /* Set while the type is being 'readied', to prevent recursive ready calls */
-#define Py_TPFLAGS_READYING (1L<<13)
+#define Py_TPFLAGS_READYING (1UL << 13)
 
 /* Objects support garbage collection (see objimp.h) */
-#define Py_TPFLAGS_HAVE_GC (1L<<14)
+#define Py_TPFLAGS_HAVE_GC (1UL << 14)
 
 /* These two bits are preserved for Stackless Python, next after this is 17 */
 #ifdef STACKLESS
-#define Py_TPFLAGS_HAVE_STACKLESS_EXTENSION (3L<<15)
+#define Py_TPFLAGS_HAVE_STACKLESS_EXTENSION (3UL << 15)
 #else
 #define Py_TPFLAGS_HAVE_STACKLESS_EXTENSION 0
 #endif
 
 /* Objects support type attribute cache */
-#define Py_TPFLAGS_HAVE_VERSION_TAG   (1L<<18)
-#define Py_TPFLAGS_VALID_VERSION_TAG  (1L<<19)
+#define Py_TPFLAGS_HAVE_VERSION_TAG   (1UL << 18)
+#define Py_TPFLAGS_VALID_VERSION_TAG  (1UL << 19)
 
 /* Type is abstract and cannot be instantiated */
-#define Py_TPFLAGS_IS_ABSTRACT (1L<<20)
+#define Py_TPFLAGS_IS_ABSTRACT (1UL << 20)
 
 /* These flags are used to determine if a type is a subclass. */
-#define Py_TPFLAGS_INT_SUBCLASS         (1L<<23)
-#define Py_TPFLAGS_LONG_SUBCLASS        (1L<<24)
-#define Py_TPFLAGS_LIST_SUBCLASS        (1L<<25)
-#define Py_TPFLAGS_TUPLE_SUBCLASS       (1L<<26)
-#define Py_TPFLAGS_BYTES_SUBCLASS       (1L<<27)
-#define Py_TPFLAGS_UNICODE_SUBCLASS     (1L<<28)
-#define Py_TPFLAGS_DICT_SUBCLASS        (1L<<29)
-#define Py_TPFLAGS_BASE_EXC_SUBCLASS    (1L<<30)
-#define Py_TPFLAGS_TYPE_SUBCLASS        (1L<<31)
+#define Py_TPFLAGS_LONG_SUBCLASS        (1UL << 24)
+#define Py_TPFLAGS_LIST_SUBCLASS        (1UL << 25)
+#define Py_TPFLAGS_TUPLE_SUBCLASS       (1UL << 26)
+#define Py_TPFLAGS_BYTES_SUBCLASS       (1UL << 27)
+#define Py_TPFLAGS_UNICODE_SUBCLASS     (1UL << 28)
+#define Py_TPFLAGS_DICT_SUBCLASS        (1UL << 29)
+#define Py_TPFLAGS_BASE_EXC_SUBCLASS    (1UL << 30)
+#define Py_TPFLAGS_TYPE_SUBCLASS        (1UL << 31)
 
 #define Py_TPFLAGS_DEFAULT  ( \
                  Py_TPFLAGS_HAVE_STACKLESS_EXTENSION | \
diff --git a/Include/objimpl.h b/Include/objimpl.h
index 3d5f509..b577be2 100644
--- a/Include/objimpl.h
+++ b/Include/objimpl.h
@@ -98,6 +98,8 @@ PyAPI_FUNC(void *) PyObject_Malloc(size_t);
 PyAPI_FUNC(void *) PyObject_Realloc(void *, size_t);
 PyAPI_FUNC(void) PyObject_Free(void *);
 
+/* This function returns the number of allocated memory blocks, regardless of size */
+PyAPI_FUNC(Py_ssize_t) _Py_GetAllocatedBlocks(void);
 
 /* Macros */
 #ifdef WITH_PYMALLOC
@@ -249,7 +251,7 @@ typedef union _gc_head {
         union _gc_head *gc_prev;
         Py_ssize_t gc_refs;
     } gc;
-    long double dummy;  /* force worst-case alignment */
+    double dummy;  /* force worst-case alignment */
 } PyGC_Head;
 
 extern PyGC_Head *_PyGC_generation0;
diff --git a/Include/osdefs.h b/Include/osdefs.h
index 05c0c8e..0c2e34b 100644
--- a/Include/osdefs.h
+++ b/Include/osdefs.h
@@ -9,16 +9,10 @@ extern "C" {
 
 /* Mod by chrish: QNX has WATCOM, but isn't DOS */
 #if !defined(__QNX__)
-#if defined(MS_WINDOWS) || defined(__BORLANDC__) || defined(__WATCOMC__) || defined(__DJGPP__) || defined(PYOS_OS2)
-#if defined(PYOS_OS2) && defined(PYCC_GCC)
-#define MAXPATHLEN 260
-#define SEP L'/'
-#define ALTSEP L'\\'
-#else
+#if defined(MS_WINDOWS) || defined(__BORLANDC__) || defined(__WATCOMC__) || defined(__DJGPP__)
 #define SEP L'\\'
 #define ALTSEP L'/'
 #define MAXPATHLEN 256
-#endif
 #define DELIM L';'
 #endif
 #endif
diff --git a/Include/patchlevel.h b/Include/patchlevel.h
index b5919a4..a759045 100644
--- a/Include/patchlevel.h
+++ b/Include/patchlevel.h
@@ -17,13 +17,13 @@
 /* Version parsed out into numeric values */
 /*--start constants--*/
 #define PY_MAJOR_VERSION	3
-#define PY_MINOR_VERSION	3
+#define PY_MINOR_VERSION	4
 #define PY_MICRO_VERSION	0
-#define PY_RELEASE_LEVEL	PY_RELEASE_LEVEL_FINAL
+#define PY_RELEASE_LEVEL	PY_RELEASE_LEVEL_ALPHA
 #define PY_RELEASE_SERIAL	0
 
 /* Version as a string */
-#define PY_VERSION      	"3.3.0+"
+#define PY_VERSION      	"3.4.0a0"
 /*--end constants--*/
 
 /* Version as a single 4-byte hex number, e.g. 0x010502B2 == 1.5.2b2.
diff --git a/Include/pyport.h b/Include/pyport.h
index e4e3601..8d38ccb 100644
--- a/Include/pyport.h
+++ b/Include/pyport.h
@@ -392,9 +392,6 @@ typedef size_t Py_uhash_t;
 #endif
 
 #ifdef HAVE_SYS_STAT_H
-#if defined(PYOS_OS2) && defined(PYCC_GCC)
-#include <sys/types.h>
-#endif
 #include <sys/stat.h>
 #elif defined(HAVE_STAT_H)
 #include <stat.h>
@@ -881,4 +878,18 @@ extern pid_t forkpty(int *, char *, struct termios *, struct winsize *);
 #endif
 #endif
 
+/*
+ * Convenient macros to deal with endianness of the platform. WORDS_BIGENDIAN is
+ * detected by configure and defined in pyconfig.h. The code in pyconfig.h
+ * also also takes care of Apple's universal builds.
+ */
+
+#ifdef WORDS_BIGENDIAN
+#define PY_BIG_ENDIAN 1
+#define PY_LITTLE_ENDIAN 0
+#else
+#define PY_BIG_ENDIAN 0
+#define PY_LITTLE_ENDIAN 1
+#endif
+
 #endif /* Py_PYPORT_H */
diff --git a/Include/sliceobject.h b/Include/sliceobject.h
index 8bec179..f7ee90c 100644
--- a/Include/sliceobject.h
+++ b/Include/sliceobject.h
@@ -34,6 +34,9 @@ PyAPI_FUNC(PyObject *) PySlice_New(PyObject* start, PyObject* stop,
                                   PyObject* step);
 #ifndef Py_LIMITED_API
 PyAPI_FUNC(PyObject *) _PySlice_FromIndices(Py_ssize_t start, Py_ssize_t stop);
+PyAPI_FUNC(int) _PySlice_GetLongIndices(PySliceObject *self, PyObject *length,
+                                 PyObject **start_ptr, PyObject **stop_ptr,
+                                 PyObject **step_ptr);
 #endif
 PyAPI_FUNC(int) PySlice_GetIndices(PyObject *r, Py_ssize_t length,
                                   Py_ssize_t *start, Py_ssize_t *stop, Py_ssize_t *step);
diff --git a/Include/symtable.h b/Include/symtable.h
index 6ed3a2b..4d82f0c 100644
--- a/Include/symtable.h
+++ b/Include/symtable.h
@@ -41,6 +41,7 @@ typedef struct _symtable_entry {
     PyObject *ste_name;      /* string: name of current block */
     PyObject *ste_varnames;  /* list of function parameters */
     PyObject *ste_children;  /* list of child blocks */
+    PyObject *ste_directives;/* locations of global and nonlocal statements */
     _Py_block_ty ste_type;   /* module, class, or function */
     int ste_unoptimized;     /* false if namespace is optimized */
     int ste_nested;      /* true if block is nested */
diff --git a/Include/token.h b/Include/token.h
index f7f6504..905022b 100644
--- a/Include/token.h
+++ b/Include/token.h
@@ -75,7 +75,7 @@ extern "C" {
 #define ISEOF(x)		((x) == ENDMARKER)
 
 
-PyAPI_DATA(char *) _PyParser_TokenNames[]; /* Token names */
+PyAPI_DATA(const char *) _PyParser_TokenNames[]; /* Token names */
 PyAPI_FUNC(int) PyToken_OneChar(int);
 PyAPI_FUNC(int) PyToken_TwoChars(int, int);
 PyAPI_FUNC(int) PyToken_ThreeChars(int, int, int);
diff --git a/Include/unicodeobject.h b/Include/unicodeobject.h
index a8f5b5d..a70585c 100644
--- a/Include/unicodeobject.h
+++ b/Include/unicodeobject.h
@@ -180,9 +180,9 @@ typedef unsigned char Py_UCS1;
     } while (0)
 
 /* macros to work with surrogates */
-#define Py_UNICODE_IS_SURROGATE(ch) (0xD800 <= ch && ch <= 0xDFFF)
-#define Py_UNICODE_IS_HIGH_SURROGATE(ch) (0xD800 <= ch && ch <= 0xDBFF)
-#define Py_UNICODE_IS_LOW_SURROGATE(ch) (0xDC00 <= ch && ch <= 0xDFFF)
+#define Py_UNICODE_IS_SURROGATE(ch) (0xD800 <= (ch) && (ch) <= 0xDFFF)
+#define Py_UNICODE_IS_HIGH_SURROGATE(ch) (0xD800 <= (ch) && (ch) <= 0xDBFF)
+#define Py_UNICODE_IS_LOW_SURROGATE(ch) (0xDC00 <= (ch) && (ch) <= 0xDFFF)
 /* Join two surrogate characters and return a single Py_UCS4 value. */
 #define Py_UNICODE_JOIN_SURROGATES(high, low)  \
     (((((Py_UCS4)(high) & 0x03FF) << 10) |      \
@@ -933,12 +933,28 @@ PyAPI_FUNC(int)
 _PyUnicodeWriter_PrepareInternal(_PyUnicodeWriter *writer,
                                  Py_ssize_t length, Py_UCS4 maxchar);
 
+/* Append a Unicode string.
+   Return 0 on success, raise an exception and return -1 on error. */
 PyAPI_FUNC(int)
-_PyUnicodeWriter_WriteStr(_PyUnicodeWriter *writer, PyObject *str);
+_PyUnicodeWriter_WriteStr(_PyUnicodeWriter *writer,
+    PyObject *str               /* Unicode string */
+    );
 
+/* Append a latin1-encoded byte string.
+   Return 0 on success, raise an exception and return -1 on error. */
+PyAPI_FUNC(int)
+_PyUnicodeWriter_WriteCstr(_PyUnicodeWriter *writer,
+    const char *str,            /* latin1-encoded byte string */
+    Py_ssize_t len              /* length in bytes */
+    );
+
+/* Get the value of the write as an Unicode string. Clear the
+   buffer of the writer. Raise an exception and return NULL
+   on error. */
 PyAPI_FUNC(PyObject *)
 _PyUnicodeWriter_Finish(_PyUnicodeWriter *writer);
 
+/* Deallocate memory of a writer (clear its internal buffer). */
 PyAPI_FUNC(void)
 _PyUnicodeWriter_Dealloc(_PyUnicodeWriter *writer);
 #endif
@@ -1726,7 +1742,7 @@ PyAPI_FUNC(PyObject*) PyUnicode_DecodeLocale(
 /* Encode a Unicode object to the current locale encoding. The encoder is
    strict is *surrogateescape* is equal to zero, otherwise the
    "surrogateescape" error handler is used. Return a bytes object. The string
-   cannot contain embedded null characters.. */
+   cannot contain embedded null characters. */
 
 PyAPI_FUNC(PyObject*) PyUnicode_EncodeLocale(
     PyObject *unicode,
@@ -1950,7 +1966,8 @@ PyAPI_FUNC(PyObject *) PyUnicode_Replace(
     );
 
 /* Compare two strings and return -1, 0, 1 for less than, equal,
-   greater than resp. */
+   greater than resp.
+   Raise an exception and return -1 on error. */
 
 PyAPI_FUNC(int) PyUnicode_Compare(
     PyObject *left,             /* Left string */
diff --git a/LICENSE b/LICENSE
index dd7044e..9716405 100644
--- a/LICENSE
+++ b/LICENSE
@@ -75,6 +75,7 @@ the various releases.
     3.2.2           3.2.1       2011        PSF         yes
     3.2.3           3.2.2       2012        PSF         yes
     3.3.0           3.2         2012        PSF         yes
+    3.4.0           3.3.0       2014        PSF         yes
 
 Footnotes:
 
diff --git a/Lib/_osx_support.py b/Lib/_osx_support.py
index b3aad56..8412e45 100644
--- a/Lib/_osx_support.py
+++ b/Lib/_osx_support.py
@@ -38,7 +38,7 @@ def _find_executable(executable, path=None):
     paths = path.split(os.pathsep)
     base, ext = os.path.splitext(executable)
 
-    if (sys.platform == 'win32' or os.name == 'os2') and (ext != '.exe'):
+    if (sys.platform == 'win32') and (ext != '.exe'):
         executable = executable + '.exe'
 
     if not os.path.isfile(executable):
@@ -94,7 +94,7 @@ def _get_system_version():
         _SYSTEM_VERSION = ''
         try:
             f = open('/System/Library/CoreServices/SystemVersion.plist')
-        except IOError:
+        except OSError:
             # We're on a plain darwin box, fall back to the default
             # behaviour.
             pass
diff --git a/Lib/_pyio.py b/Lib/_pyio.py
index 9cbb364..5ff9c0f 100644
--- a/Lib/_pyio.py
+++ b/Lib/_pyio.py
@@ -34,7 +34,7 @@ BlockingIOError = BlockingIOError
 def open(file, mode="r", buffering=-1, encoding=None, errors=None,
          newline=None, closefd=True, opener=None):
 
-    r"""Open file and return a stream.  Raise IOError upon failure.
+    r"""Open file and return a stream.  Raise OSError upon failure.
 
     file is either a text or byte string giving the name (and the path
     if the file isn't in the current working directory) of the file to
@@ -200,7 +200,7 @@ def open(file, mode="r", buffering=-1, encoding=None, errors=None,
         buffering = DEFAULT_BUFFER_SIZE
         try:
             bs = os.fstat(raw.fileno()).st_blksize
-        except (os.error, AttributeError):
+        except (OSError, AttributeError):
             pass
         else:
             if bs > 1:
@@ -254,7 +254,7 @@ class OpenWrapper:
 try:
     UnsupportedOperation = io.UnsupportedOperation
 except AttributeError:
-    class UnsupportedOperation(ValueError, IOError):
+    class UnsupportedOperation(ValueError, OSError):
         pass
 
 
@@ -278,7 +278,7 @@ class IOBase(metaclass=abc.ABCMeta):
     readinto) needed. Text I/O classes work with str data.
 
     Note that calling any method (even inquiries) on a closed stream is
-    undefined. Implementations may raise IOError in this case.
+    undefined. Implementations may raise OSError in this case.
 
     IOBase (and its subclasses) support the iterator protocol, meaning
     that an IOBase object can be iterated over yielding the lines in a
@@ -294,7 +294,7 @@ class IOBase(metaclass=abc.ABCMeta):
     ### Internal ###
 
     def _unsupported(self, name):
-        """Internal: raise an IOError exception for unsupported operations."""
+        """Internal: raise an OSError exception for unsupported operations."""
         raise UnsupportedOperation("%s.%s() not supported" %
                                    (self.__class__.__name__, name))
 
@@ -441,7 +441,7 @@ class IOBase(metaclass=abc.ABCMeta):
     def fileno(self):
         """Returns underlying file descriptor (an int) if one exists.
 
-        An IOError is raised if the IO object does not use a file descriptor.
+        An OSError is raised if the IO object does not use a file descriptor.
         """
         self._unsupported("fileno")
 
@@ -699,13 +699,13 @@ class _BufferedIOMixin(BufferedIOBase):
     def seek(self, pos, whence=0):
         new_position = self.raw.seek(pos, whence)
         if new_position < 0:
-            raise IOError("seek() returned an invalid position")
+            raise OSError("seek() returned an invalid position")
         return new_position
 
     def tell(self):
         pos = self.raw.tell()
         if pos < 0:
-            raise IOError("tell() returned an invalid position")
+            raise OSError("tell() returned an invalid position")
         return pos
 
     def truncate(self, pos=None):
@@ -927,7 +927,7 @@ class BufferedReader(_BufferedIOMixin):
         """Create a new buffered reader using the given readable raw IO object.
         """
         if not raw.readable():
-            raise IOError('"raw" argument must be readable.')
+            raise OSError('"raw" argument must be readable.')
 
         _BufferedIOMixin.__init__(self, raw)
         if buffer_size <= 0:
@@ -1074,7 +1074,7 @@ class BufferedWriter(_BufferedIOMixin):
 
     def __init__(self, raw, buffer_size=DEFAULT_BUFFER_SIZE):
         if not raw.writable():
-            raise IOError('"raw" argument must be writable.')
+            raise OSError('"raw" argument must be writable.')
 
         _BufferedIOMixin.__init__(self, raw)
         if buffer_size <= 0:
@@ -1138,7 +1138,7 @@ class BufferedWriter(_BufferedIOMixin):
                     errno.EAGAIN,
                     "write could not complete without blocking", 0)
             if n > len(self._write_buf) or n < 0:
-                raise IOError("write() returned incorrect number of bytes")
+                raise OSError("write() returned incorrect number of bytes")
             del self._write_buf[:n]
 
     def tell(self):
@@ -1174,10 +1174,10 @@ class BufferedRWPair(BufferedIOBase):
         The arguments are two RawIO instances.
         """
         if not reader.readable():
-            raise IOError('"reader" argument must be readable.')
+            raise OSError('"reader" argument must be readable.')
 
         if not writer.writable():
-            raise IOError('"writer" argument must be writable.')
+            raise OSError('"writer" argument must be writable.')
 
         self.reader = BufferedReader(reader, buffer_size)
         self.writer = BufferedWriter(writer, buffer_size)
@@ -1248,7 +1248,7 @@ class BufferedRandom(BufferedWriter, BufferedReader):
         with self._read_lock:
             self._reset_read_buf()
         if pos < 0:
-            raise IOError("seek() returned invalid position")
+            raise OSError("seek() returned invalid position")
         return pos
 
     def tell(self):
@@ -1727,7 +1727,7 @@ class TextIOWrapper(TextIOBase):
         if not self._seekable:
             raise UnsupportedOperation("underlying stream is not seekable")
         if not self._telling:
-            raise IOError("telling position disabled by next() call")
+            raise OSError("telling position disabled by next() call")
         self.flush()
         position = self.buffer.tell()
         decoder = self._decoder
@@ -1814,7 +1814,7 @@ class TextIOWrapper(TextIOBase):
                 chars_decoded += len(decoder.decode(b'', final=True))
                 need_eof = 1
                 if chars_decoded < chars_to_skip:
-                    raise IOError("can't reconstruct logical file position")
+                    raise OSError("can't reconstruct logical file position")
 
             # The returned cookie corresponds to the last safe start point.
             return self._pack_cookie(
@@ -1891,7 +1891,7 @@ class TextIOWrapper(TextIOBase):
 
             # Skip chars_to_skip of the decoded characters.
             if len(self._decoded_chars) < chars_to_skip:
-                raise IOError("can't restore logical file position")
+                raise OSError("can't restore logical file position")
             self._decoded_chars_used = chars_to_skip
 
         # Finally, reset the encoder (merely useful for proper BOM handling)
diff --git a/Lib/abc.py b/Lib/abc.py
index 09778e8..e807895 100644
--- a/Lib/abc.py
+++ b/Lib/abc.py
@@ -226,3 +226,9 @@ class ABCMeta(type):
         # No dice; update negative cache
         cls._abc_negative_cache.add(subclass)
         return False
+
+class ABC(metaclass=ABCMeta):
+    """Helper class that provides a standard way to create an ABC using
+    inheritance.
+    """
+    pass
diff --git a/Lib/aifc.py b/Lib/aifc.py
index a19b38f..67ea5da 100644
--- a/Lib/aifc.py
+++ b/Lib/aifc.py
@@ -334,6 +334,12 @@ class Aifc_read:
         # else, assume it is an open file object already
         self.initfp(f)
 
+    def __enter__(self):
+        return self
+
+    def __exit__(self, *args):
+        self.close()
+
     #
     # User visible methods.
     #
@@ -553,6 +559,12 @@ class Aifc_write:
     def __del__(self):
         self.close()
 
+    def __enter__(self):
+        return self
+
+    def __exit__(self, *args):
+        self.close()
+
     #
     # User visible methods.
     #
diff --git a/Lib/argparse.py b/Lib/argparse.py
index f25b1b6..1c07110 100644
--- a/Lib/argparse.py
+++ b/Lib/argparse.py
@@ -606,8 +606,7 @@ class HelpFormatter(object):
             pass
         else:
             self._indent()
-            for subaction in get_subactions():
-                yield subaction
+            yield from get_subactions()
             self._dedent()
 
     def _split_lines(self, text, width):
@@ -1141,11 +1140,17 @@ class FileType(object):
             same values as the builtin open() function.
         - bufsize -- The file's desired buffer size. Accepts the same values as
             the builtin open() function.
+        - encoding -- The file's encoding. Accepts the same values as the
+            the builtin open() function.
+        - errors -- A string indicating how encoding and decoding errors are to
+            be handled. Accepts the same value as the builtin open() function.
     """
 
-    def __init__(self, mode='r', bufsize=-1):
+    def __init__(self, mode='r', bufsize=-1, encoding=None, errors=None):
         self._mode = mode
         self._bufsize = bufsize
+        self._encoding = encoding
+        self._errors = errors
 
     def __call__(self, string):
         # the special argument "-" means sys.std{in,out}
@@ -1160,14 +1165,18 @@ class FileType(object):
 
         # all other arguments are used as file names
         try:
-            return open(string, self._mode, self._bufsize)
-        except IOError as e:
+            return open(string, self._mode, self._bufsize, self._encoding,
+                        self._errors)
+        except OSError as e:
             message = _("can't open '%s': %s")
             raise ArgumentTypeError(message % (string, e))
 
     def __repr__(self):
         args = self._mode, self._bufsize
-        args_str = ', '.join(repr(arg) for arg in args if arg != -1)
+        kwargs = [('encoding', self._encoding), ('errors', self._errors)]
+        args_str = ', '.join([repr(arg) for arg in args if arg != -1] +
+                             ['%s=%r' % (kw, arg) for kw, arg in kwargs
+                              if arg is not None])
         return '%s(%s)' % (type(self).__name__, args_str)
 
 # ===========================
@@ -2011,7 +2020,7 @@ class ArgumentParser(_AttributeHolder, _ActionsContainer):
                         new_arg_strings.extend(arg_strings)
                     finally:
                         args_file.close()
-                except IOError:
+                except OSError:
                     err = _sys.exc_info()[1]
                     self.error(str(err))
 
diff --git a/Lib/ast.py b/Lib/ast.py
index 13f59f9..02c3b28 100644
--- a/Lib/ast.py
+++ b/Lib/ast.py
@@ -42,7 +42,6 @@ def literal_eval(node_or_string):
     Python literal structures: strings, bytes, numbers, tuples, lists, dicts,
     sets, booleans, and None.
     """
-    _safe_names = {'None': None, 'True': True, 'False': False}
     if isinstance(node_or_string, str):
         node_or_string = parse(node_or_string, mode='eval')
     if isinstance(node_or_string, Expression):
@@ -61,9 +60,8 @@ def literal_eval(node_or_string):
         elif isinstance(node, Dict):
             return dict((_convert(k), _convert(v)) for k, v
                         in zip(node.keys, node.values))
-        elif isinstance(node, Name):
-            if node.id in _safe_names:
-                return _safe_names[node.id]
+        elif isinstance(node, NameConstant):
+            return node.value
         elif isinstance(node, UnaryOp) and \
              isinstance(node.op, (UAdd, USub)) and \
              isinstance(node.operand, (Num, UnaryOp, BinOp)):
diff --git a/Lib/asynchat.py b/Lib/asynchat.py
index 4e26bb5..f055d63 100644
--- a/Lib/asynchat.py
+++ b/Lib/asynchat.py
@@ -56,8 +56,8 @@ class async_chat (asyncore.dispatcher):
 
     # these are overridable defaults
 
-    ac_in_buffer_size       = 4096
-    ac_out_buffer_size      = 4096
+    ac_in_buffer_size       = 65536
+    ac_out_buffer_size      = 65536
 
     # we don't want to enable the use of encoding by default, because that is a
     # sign of an application bug that we don't want to pass silently
@@ -114,7 +114,7 @@ class async_chat (asyncore.dispatcher):
 
         try:
             data = self.recv (self.ac_in_buffer_size)
-        except socket.error as why:
+        except OSError as why:
             self.handle_error()
             return
 
@@ -243,7 +243,7 @@ class async_chat (asyncore.dispatcher):
             # send the data
             try:
                 num_sent = self.send(data)
-            except socket.error:
+            except OSError:
                 self.handle_error()
                 return
 
diff --git a/Lib/asyncore.py b/Lib/asyncore.py
index 909d9f6..f146643 100644
--- a/Lib/asyncore.py
+++ b/Lib/asyncore.py
@@ -112,7 +112,7 @@ def readwrite(obj, flags):
             obj.handle_expt_event()
         if flags & (select.POLLHUP | select.POLLERR | select.POLLNVAL):
             obj.handle_close()
-    except socket.error as e:
+    except OSError as e:
         if e.args[0] not in _DISCONNECTED:
             obj.handle_error()
         else:
@@ -240,7 +240,7 @@ class dispatcher:
             # passed be connected.
             try:
                 self.addr = sock.getpeername()
-            except socket.error as err:
+            except OSError as err:
                 if err.args[0] in (ENOTCONN, EINVAL):
                     # To handle the case where we got an unconnected
                     # socket.
@@ -304,7 +304,7 @@ class dispatcher:
                 self.socket.getsockopt(socket.SOL_SOCKET,
                                        socket.SO_REUSEADDR) | 1
                 )
-        except socket.error:
+        except OSError:
             pass
 
     # ==================================================
@@ -345,7 +345,7 @@ class dispatcher:
             self.addr = address
             self.handle_connect_event()
         else:
-            raise socket.error(err, errorcode[err])
+            raise OSError(err, errorcode[err])
 
     def accept(self):
         # XXX can return either an address pair or None
@@ -353,7 +353,7 @@ class dispatcher:
             conn, addr = self.socket.accept()
         except TypeError:
             return None
-        except socket.error as why:
+        except OSError as why:
             if why.args[0] in (EWOULDBLOCK, ECONNABORTED, EAGAIN):
                 return None
             else:
@@ -365,7 +365,7 @@ class dispatcher:
         try:
             result = self.socket.send(data)
             return result
-        except socket.error as why:
+        except OSError as why:
             if why.args[0] == EWOULDBLOCK:
                 return 0
             elif why.args[0] in _DISCONNECTED:
@@ -384,7 +384,7 @@ class dispatcher:
                 return b''
             else:
                 return data
-        except socket.error as why:
+        except OSError as why:
             # winsock sometimes raises ENOTCONN
             if why.args[0] in _DISCONNECTED:
                 self.handle_close()
@@ -399,7 +399,7 @@ class dispatcher:
         self.del_channel()
         try:
             self.socket.close()
-        except socket.error as why:
+        except OSError as why:
             if why.args[0] not in (ENOTCONN, EBADF):
                 raise
 
@@ -443,7 +443,7 @@ class dispatcher:
     def handle_connect_event(self):
         err = self.socket.getsockopt(socket.SOL_SOCKET, socket.SO_ERROR)
         if err != 0:
-            raise socket.error(err, _strerror(err))
+            raise OSError(err, _strerror(err))
         self.handle_connect()
         self.connected = True
         self.connecting = False
@@ -532,7 +532,7 @@ class dispatcher_with_send(dispatcher):
 
     def initiate_send(self):
         num_sent = 0
-        num_sent = dispatcher.send(self, self.out_buffer[:512])
+        num_sent = dispatcher.send(self, self.out_buffer[:65536])
         self.out_buffer = self.out_buffer[num_sent:]
 
     def handle_write(self):
diff --git a/Lib/bz2.py b/Lib/bz2.py
index c307507..6e6a2b9 100644
--- a/Lib/bz2.py
+++ b/Lib/bz2.py
@@ -9,7 +9,6 @@ __all__ = ["BZ2File", "BZ2Compressor", "BZ2Decompressor",
 
 __author__ = "Nadeem Vawda <nadeem.vawda@gmail.com>"
 
-import builtins
 import io
 import warnings
 
@@ -28,6 +27,8 @@ _MODE_WRITE    = 3
 
 _BUFFER_SIZE = 8192
 
+_builtin_open = open
+
 
 class BZ2File(io.BufferedIOBase):
 
@@ -43,12 +44,13 @@ class BZ2File(io.BufferedIOBase):
     def __init__(self, filename, mode="r", buffering=None, compresslevel=9):
         """Open a bzip2-compressed file.
 
-        If filename is a str or bytes object, is gives the name of the file to
-        be opened. Otherwise, it should be a file object, which will be used to
-        read or write the compressed data.
+        If filename is a str or bytes object, it gives the name
+        of the file to be opened. Otherwise, it should be a file object,
+        which will be used to read or write the compressed data.
 
-        mode can be 'r' for reading (default), 'w' for (over)writing, or 'a' for
-        appending. These can equivalently be given as 'rb', 'wb', and 'ab'.
+        mode can be 'r' for reading (default), 'w' for (over)writing,
+        or 'a' for appending. These can equivalently be given as 'rb',
+        'wb', and 'ab'.
 
         buffering is ignored. Its use is deprecated.
 
@@ -90,10 +92,10 @@ class BZ2File(io.BufferedIOBase):
             mode_code = _MODE_WRITE
             self._compressor = BZ2Compressor(compresslevel)
         else:
-            raise ValueError("Invalid mode: {!r}".format(mode))
+            raise ValueError("Invalid mode: %r" % (mode,))
 
         if isinstance(filename, (str, bytes)):
-            self._fp = builtins.open(filename, mode)
+            self._fp = _builtin_open(filename, mode)
             self._closefp = True
             self._mode = mode_code
         elif hasattr(filename, "read") or hasattr(filename, "write"):
@@ -189,15 +191,17 @@ class BZ2File(io.BufferedIOBase):
 
             if not rawblock:
                 if self._decompressor.eof:
+                    # End-of-stream marker and end of file. We're good.
                     self._mode = _MODE_READ_EOF
                     self._size = self._pos
                     return False
                 else:
+                    # Problem - we were expecting more compressed data.
                     raise EOFError("Compressed file ended before the "
                                    "end-of-stream marker was reached")
 
-            # Continue to next stream.
             if self._decompressor.eof:
+                # Continue to next stream.
                 self._decompressor = BZ2Decompressor()
 
             self._buffer = self._decompressor.decompress(rawblock)
@@ -412,7 +416,7 @@ class BZ2File(io.BufferedIOBase):
                     self._read_all(return_data=False)
                 offset = self._size + offset
             else:
-                raise ValueError("Invalid value for whence: {}".format(whence))
+                raise ValueError("Invalid value for whence: %s" % (whence,))
 
             # Make it so that offset is the number of bytes to skip forward.
             if offset < self._pos:
@@ -436,20 +440,20 @@ def open(filename, mode="rb", compresslevel=9,
          encoding=None, errors=None, newline=None):
     """Open a bzip2-compressed file in binary or text mode.
 
-    The filename argument can be an actual filename (a str or bytes object), or
-    an existing file object to read from or write to.
+    The filename argument can be an actual filename (a str or bytes
+    object), or an existing file object to read from or write to.
 
-    The mode argument can be "r", "rb", "w", "wb", "a" or "ab" for binary mode,
-    or "rt", "wt" or "at" for text mode. The default mode is "rb", and the
-    default compresslevel is 9.
+    The mode argument can be "r", "rb", "w", "wb", "a" or "ab" for
+    binary mode, or "rt", "wt" or "at" for text mode. The default mode
+    is "rb", and the default compresslevel is 9.
 
-    For binary mode, this function is equivalent to the BZ2File constructor:
-    BZ2File(filename, mode, compresslevel). In this case, the encoding, errors
-    and newline arguments must not be provided.
+    For binary mode, this function is equivalent to the BZ2File
+    constructor: BZ2File(filename, mode, compresslevel). In this case,
+    the encoding, errors and newline arguments must not be provided.
 
     For text mode, a BZ2File object is created, and wrapped in an
-    io.TextIOWrapper instance with the specified encoding, error handling
-    behavior, and line ending(s).
+    io.TextIOWrapper instance with the specified encoding, error
+    handling behavior, and line ending(s).
 
     """
     if "t" in mode:
diff --git a/Lib/cgi.py b/Lib/cgi.py
index 96b1f57..385a57c 100755
--- a/Lib/cgi.py
+++ b/Lib/cgi.py
@@ -80,7 +80,7 @@ def initlog(*allargs):
     if logfile and not logfp:
         try:
             logfp = open(logfile, "a")
-        except IOError:
+        except OSError:
             pass
     if not logfp:
         log = nolog
@@ -949,8 +949,8 @@ def print_directory():
     print("<H3>Current Working Directory:</H3>")
     try:
         pwd = os.getcwd()
-    except os.error as msg:
-        print("os.error:", html.escape(str(msg)))
+    except OSError as msg:
+        print("OSError:", html.escape(str(msg)))
     else:
         print(html.escape(pwd))
     print()
diff --git a/Lib/chunk.py b/Lib/chunk.py
index 5863ed0..dc90a75 100644
--- a/Lib/chunk.py
+++ b/Lib/chunk.py
@@ -70,7 +70,7 @@ class Chunk:
         self.size_read = 0
         try:
             self.offset = self.file.tell()
-        except (AttributeError, IOError):
+        except (AttributeError, OSError):
             self.seekable = False
         else:
             self.seekable = True
@@ -102,7 +102,7 @@ class Chunk:
         if self.closed:
             raise ValueError("I/O operation on closed file")
         if not self.seekable:
-            raise IOError("cannot seek")
+            raise OSError("cannot seek")
         if whence == 1:
             pos = pos + self.size_read
         elif whence == 2:
@@ -158,7 +158,7 @@ class Chunk:
                 self.file.seek(n, 1)
                 self.size_read = self.size_read + n
                 return
-            except IOError:
+            except OSError:
                 pass
         while self.size_read < self.chunksize:
             n = min(8192, self.chunksize - self.size_read)
diff --git a/Lib/collections/__init__.py b/Lib/collections/__init__.py
index e5f9599..0612e1f 100644
--- a/Lib/collections/__init__.py
+++ b/Lib/collections/__init__.py
@@ -228,8 +228,7 @@ class OrderedDict(dict):
 
         '''
         if isinstance(other, OrderedDict):
-            return len(self)==len(other) and \
-                   all(map(_eq, self.items(), other.items()))
+            return dict.__eq__(self, other) and all(map(_eq, self, other))
         return dict.__eq__(self, other)
 
 
@@ -822,9 +821,14 @@ class ChainMap(MutableMapping):
 
     __copy__ = copy
 
-    def new_child(self):                        # like Django's Context.push()
-        'New ChainMap with a new dict followed by all previous maps.'
-        return self.__class__({}, *self.maps)
+    def new_child(self, m=None):                # like Django's Context.push()
+        '''
+        New ChainMap with a new map followed by all previous maps. If no
+        map is provided, an empty dict is used.
+        '''
+        if m is None:
+            m = {}
+        return self.__class__(m, *self.maps)
 
     @property
     def parents(self):                          # like Django's Context.pop()
diff --git a/Lib/collections/abc.py b/Lib/collections/abc.py
index c23b7dd..18c07bf 100644
--- a/Lib/collections/abc.py
+++ b/Lib/collections/abc.py
@@ -430,8 +430,7 @@ class KeysView(MappingView, Set):
         return key in self._mapping
 
     def __iter__(self):
-        for key in self._mapping:
-            yield key
+        yield from self._mapping
 
 KeysView.register(dict_keys)
 
diff --git a/Lib/compileall.py b/Lib/compileall.py
index d3cff6a..a8e9a31 100644
--- a/Lib/compileall.py
+++ b/Lib/compileall.py
@@ -38,7 +38,7 @@ def compile_dir(dir, maxlevels=10, ddir=None, force=False, rx=None,
         print('Listing {!r}...'.format(dir))
     try:
         names = os.listdir(dir)
-    except os.error:
+    except OSError:
         print("Can't list {!r}".format(dir))
         names = []
     names.sort()
@@ -106,7 +106,7 @@ def compile_file(fullname, ddir=None, force=False, rx=None, quiet=False,
                         actual = chandle.read(8)
                     if expect == actual:
                         return success
-                except IOError:
+                except OSError:
                     pass
             if not quiet:
                 print('Compiling {!r}...'.format(fullname))
@@ -124,7 +124,7 @@ def compile_file(fullname, ddir=None, force=False, rx=None, quiet=False,
                 msg = msg.decode(sys.stdout.encoding)
                 print(msg)
                 success = 0
-            except (SyntaxError, UnicodeError, IOError) as e:
+            except (SyntaxError, UnicodeError, OSError) as e:
                 if quiet:
                     print('*** Error compiling {!r}...'.format(fullname))
                 else:
@@ -209,7 +209,7 @@ def main():
             with (sys.stdin if args.flist=='-' else open(args.flist)) as f:
                 for line in f:
                     compile_dests.append(line.strip())
-        except EnvironmentError:
+        except OSError:
             print("Error reading file list {}".format(args.flist))
             return False
 
diff --git a/Lib/concurrent/futures/_base.py b/Lib/concurrent/futures/_base.py
index e997c02..e9f6537 100644
--- a/Lib/concurrent/futures/_base.py
+++ b/Lib/concurrent/futures/_base.py
@@ -198,8 +198,7 @@ def as_completed(fs, timeout=None):
         waiter = _create_and_install_waiters(fs, _AS_COMPLETED)
 
     try:
-        for future in finished:
-            yield future
+        yield from finished
 
         while pending:
             if timeout is None:
diff --git a/Lib/concurrent/futures/process.py b/Lib/concurrent/futures/process.py
index 04238a7..3c20b93 100644
--- a/Lib/concurrent/futures/process.py
+++ b/Lib/concurrent/futures/process.py
@@ -40,7 +40,7 @@ Local worker thread:
 
 Process #1..n:
 - reads _CallItems from "Call Q", executes the calls, and puts the resulting
-  _ResultItems in "Request Q"
+  _ResultItems in "Result Q"
 """
 
 __author__ = 'Brian Quinlan (brian@sweetapp.com)'
@@ -240,6 +240,8 @@ def _queue_management_worker(executor_reference,
                         "terminated abruptly while the future was "
                         "running or pending."
                     ))
+                # Delete references to object. See issue16284
+                del work_item
             pending_work_items.clear()
             # Terminate remaining workers forcibly: the queues or their
             # locks may be in a dirty state and block forever.
@@ -264,6 +266,8 @@ def _queue_management_worker(executor_reference,
                     work_item.future.set_exception(result_item.exception)
                 else:
                     work_item.future.set_result(result_item.result)
+                # Delete references to object. See issue16284
+                del work_item
         # Check whether we should start shutting down.
         executor = executor_reference()
         # No more work items can be added if:
diff --git a/Lib/concurrent/futures/thread.py b/Lib/concurrent/futures/thread.py
index 95bb682..f9beb0f 100644
--- a/Lib/concurrent/futures/thread.py
+++ b/Lib/concurrent/futures/thread.py
@@ -63,6 +63,8 @@ def _worker(executor_reference, work_queue):
             work_item = work_queue.get(block=True)
             if work_item is not None:
                 work_item.run()
+                # Delete references to object. See issue16284
+                del work_item
                 continue
             executor = executor_reference()
             # Exit if:
diff --git a/Lib/configparser.py b/Lib/configparser.py
index c7bee6b..f9584cd 100644
--- a/Lib/configparser.py
+++ b/Lib/configparser.py
@@ -687,7 +687,7 @@ class RawConfigParser(MutableMapping):
             try:
                 with open(filename, encoding=encoding) as fp:
                     self._read(fp, filename)
-            except IOError:
+            except OSError:
                 continue
             read_ok.append(filename)
         return read_ok
diff --git a/Lib/ctypes/__init__.py b/Lib/ctypes/__init__.py
index c92e130..e2f75c5 100644
--- a/Lib/ctypes/__init__.py
+++ b/Lib/ctypes/__init__.py
@@ -395,7 +395,7 @@ if _os.name in ("nt", "ce"):
         _type_ = "l"
         # _check_retval_ is called with the function's result when it
         # is used as restype.  It checks for the FAILED bit, and
-        # raises a WindowsError if it is set.
+        # raises an OSError if it is set.
         #
         # The _check_retval_ method is implemented in C, so that the
         # method definition itself is not included in the traceback
@@ -407,7 +407,7 @@ if _os.name in ("nt", "ce"):
     class OleDLL(CDLL):
         """This class represents a dll exporting functions using the
         Windows stdcall calling convention, and returning HRESULT.
-        HRESULT error values are automatically raised as WindowsError
+        HRESULT error values are automatically raised as OSError
         exceptions.
         """
         _func_flags_ = _FUNCFLAG_STDCALL
@@ -456,7 +456,7 @@ if _os.name in ("nt", "ce"):
             code = GetLastError()
         if descr is None:
             descr = FormatError(code).strip()
-        return WindowsError(None, descr, None, code)
+        return OSError(None, descr, None, code)
 
 if sizeof(c_uint) == sizeof(c_void_p):
     c_size_t = c_uint
diff --git a/Lib/ctypes/test/test_checkretval.py b/Lib/ctypes/test/test_checkretval.py
index 01ccc57..19bb813 100644
--- a/Lib/ctypes/test/test_checkretval.py
+++ b/Lib/ctypes/test/test_checkretval.py
@@ -31,7 +31,7 @@ class Test(unittest.TestCase):
         pass
     else:
         def test_oledll(self):
-            self.assertRaises(WindowsError,
+            self.assertRaises(OSError,
                                   oledll.oleaut32.CreateTypeLib2,
                                   0, None, None)
 
diff --git a/Lib/ctypes/test/test_win32.py b/Lib/ctypes/test/test_win32.py
index da21336..91ad314 100644
--- a/Lib/ctypes/test/test_win32.py
+++ b/Lib/ctypes/test/test_win32.py
@@ -41,7 +41,7 @@ if sys.platform == "win32":
                 # Call functions with invalid arguments, and make sure
                 # that access violations are trapped and raise an
                 # exception.
-                self.assertRaises(WindowsError, windll.kernel32.GetModuleHandleA, 32)
+                self.assertRaises(OSError, windll.kernel32.GetModuleHandleA, 32)
 
         def test_noargs(self):
             # This is a special case on win32 x64
diff --git a/Lib/dbm/__init__.py b/Lib/dbm/__init__.py
index 813a29d..0609e49 100644
--- a/Lib/dbm/__init__.py
+++ b/Lib/dbm/__init__.py
@@ -42,7 +42,7 @@ _names = ['dbm.gnu', 'dbm.ndbm', 'dbm.dumb']
 _defaultmod = None
 _modules = {}
 
-error = (error, IOError)
+error = (error, OSError)
 
 
 def open(file, flag='r', mode=0o666):
@@ -106,12 +106,10 @@ def whichdb(filename):
     try:
         f = io.open(filename + ".pag", "rb")
         f.close()
-        # dbm linked with gdbm on OS/2 doesn't have .dir file
-        if not (ndbm.library == "GNU gdbm" and sys.platform == "os2emx"):
-            f = io.open(filename + ".dir", "rb")
-            f.close()
+        f = io.open(filename + ".dir", "rb")
+        f.close()
         return "dbm.ndbm"
-    except IOError:
+    except OSError:
         # some dbm emulations based on Berkeley DB generate a .db file
         # some do not, but they should be caught by the bsd checks
         try:
@@ -124,7 +122,7 @@ def whichdb(filename):
                 d = ndbm.open(filename)
                 d.close()
                 return "dbm.ndbm"
-        except IOError:
+        except OSError:
             pass
 
     # Check for dumbdbm next -- this has a .dir and a .dat file
@@ -141,13 +139,13 @@ def whichdb(filename):
                 return "dbm.dumb"
         finally:
             f.close()
-    except (OSError, IOError):
+    except OSError:
         pass
 
     # See if the file exists, return None if not
     try:
         f = io.open(filename, "rb")
-    except IOError:
+    except OSError:
         return None
 
     # Read the start of the file -- the magic number
diff --git a/Lib/dbm/dumb.py b/Lib/dbm/dumb.py
index cfb9123..9ac7852 100644
--- a/Lib/dbm/dumb.py
+++ b/Lib/dbm/dumb.py
@@ -29,7 +29,7 @@ __all__ = ["error", "open"]
 
 _BLOCKSIZE = 512
 
-error = IOError
+error = OSError
 
 class _Database(collections.MutableMapping):
 
@@ -67,7 +67,7 @@ class _Database(collections.MutableMapping):
         # Mod by Jack: create data file if needed
         try:
             f = _io.open(self._datfile, 'r', encoding="Latin-1")
-        except IOError:
+        except OSError:
             f = _io.open(self._datfile, 'w', encoding="Latin-1")
             self._chmod(self._datfile)
         f.close()
@@ -78,7 +78,7 @@ class _Database(collections.MutableMapping):
         self._index = {}
         try:
             f = _io.open(self._dirfile, 'r', encoding="Latin-1")
-        except IOError:
+        except OSError:
             pass
         else:
             for line in f:
@@ -100,12 +100,12 @@ class _Database(collections.MutableMapping):
 
         try:
             self._os.unlink(self._bakfile)
-        except self._os.error:
+        except OSError:
             pass
 
         try:
             self._os.rename(self._dirfile, self._bakfile)
-        except self._os.error:
+        except OSError:
             pass
 
         f = self._io.open(self._dirfile, 'w', encoding="Latin-1")
diff --git a/Lib/decimal.py b/Lib/decimal.py
index 746b34a..25f8fbc 100644
--- a/Lib/decimal.py
+++ b/Lib/decimal.py
@@ -703,8 +703,7 @@ class Decimal(object):
 
         raise TypeError("Cannot convert %r to Decimal" % value)
 
-    # @classmethod, but @decorator is not valid Python 2.3 syntax, so
-    # don't use it (see notes on Py2.3 compatibility at top of file)
+    @classmethod
     def from_float(cls, f):
         """Converts a float to a decimal number, exactly.
 
@@ -743,7 +742,6 @@ class Decimal(object):
             return result
         else:
             return cls(result)
-    from_float = classmethod(from_float)
 
     def _isnan(self):
         """Returns whether the number is not actually one.
diff --git a/Lib/difflib.py b/Lib/difflib.py
index ae377d7..db5f82e 100644
--- a/Lib/difflib.py
+++ b/Lib/difflib.py
@@ -922,8 +922,7 @@ class Differ:
             else:
                 raise ValueError('unknown tag %r' % (tag,))
 
-            for line in g:
-                yield line
+            yield from g
 
     def _dump(self, tag, x, lo, hi):
         """Generate comparison results for a same-tagged range."""
@@ -942,8 +941,7 @@ class Differ:
             second = self._dump('+', b, blo, bhi)
 
         for g in first, second:
-            for line in g:
-                yield line
+            yield from g
 
     def _fancy_replace(self, a, alo, ahi, b, blo, bhi):
         r"""
@@ -997,8 +995,7 @@ class Differ:
             # no non-identical "pretty close" pair
             if eqi is None:
                 # no identical pair either -- treat it as a straight replace
-                for line in self._plain_replace(a, alo, ahi, b, blo, bhi):
-                    yield line
+                yield from self._plain_replace(a, alo, ahi, b, blo, bhi)
                 return
             # no close pair, but an identical pair -- synch up on that
             best_i, best_j, best_ratio = eqi, eqj, 1.0
@@ -1010,8 +1007,7 @@ class Differ:
         # identical
 
         # pump out diffs from before the synch point
-        for line in self._fancy_helper(a, alo, best_i, b, blo, best_j):
-            yield line
+        yield from self._fancy_helper(a, alo, best_i, b, blo, best_j)
 
         # do intraline marking on the synch pair
         aelt, belt = a[best_i], b[best_j]
@@ -1033,15 +1029,13 @@ class Differ:
                     btags += ' ' * lb
                 else:
                     raise ValueError('unknown tag %r' % (tag,))
-            for line in self._qformat(aelt, belt, atags, btags):
-                yield line
+            yield from self._qformat(aelt, belt, atags, btags)
         else:
             # the synch pair is identical
             yield '  ' + aelt
 
         # pump out diffs from after the synch point
-        for line in self._fancy_helper(a, best_i+1, ahi, b, best_j+1, bhi):
-            yield line
+        yield from self._fancy_helper(a, best_i+1, ahi, b, best_j+1, bhi)
 
     def _fancy_helper(self, a, alo, ahi, b, blo, bhi):
         g = []
@@ -1053,8 +1047,7 @@ class Differ:
         elif blo < bhi:
             g = self._dump('+', b, blo, bhi)
 
-        for line in g:
-            yield line
+        yield from g
 
     def _qformat(self, aline, bline, atags, btags):
         r"""
diff --git a/Lib/distutils/__init__.py b/Lib/distutils/__init__.py
index 345ac4f..70a72b0 100644
--- a/Lib/distutils/__init__.py
+++ b/Lib/distutils/__init__.py
@@ -13,5 +13,5 @@ used from a setup script as
 # Updated automatically by the Python release process.
 #
 #--start constants--
-__version__ = "3.3.0"
+__version__ = "3.4.0a0"
 #--end constants--
diff --git a/Lib/distutils/ccompiler.py b/Lib/distutils/ccompiler.py
index c795c95..911e84d 100644
--- a/Lib/distutils/ccompiler.py
+++ b/Lib/distutils/ccompiler.py
@@ -351,7 +351,7 @@ class CCompiler:
         return macros, objects, extra, pp_opts, build
 
     def _get_cc_args(self, pp_opts, debug, before):
-        # works for unixccompiler, emxccompiler, cygwinccompiler
+        # works for unixccompiler, cygwinccompiler
         cc_args = pp_opts + ['-c']
         if debug:
             cc_args[:0] = ['-g']
@@ -926,7 +926,6 @@ _default_compilers = (
     # on a cygwin built python we can use gcc like an ordinary UNIXish
     # compiler
     ('cygwin.*', 'unix'),
-    ('os2emx', 'emx'),
 
     # OS name mappings
     ('posix', 'unix'),
@@ -968,8 +967,6 @@ compiler_class = { 'unix':    ('unixccompiler', 'UnixCCompiler',
                                "Mingw32 port of GNU C Compiler for Win32"),
                    'bcpp':    ('bcppcompiler', 'BCPPCompiler',
                                "Borland C++ Compiler"),
-                   'emx':     ('emxccompiler', 'EMXCCompiler',
-                               "EMX port of GNU C Compiler for OS/2"),
                  }
 
 def show_compilers():
diff --git a/Lib/distutils/command/bdist.py b/Lib/distutils/command/bdist.py
index c5188eb..38b169a 100644
--- a/Lib/distutils/command/bdist.py
+++ b/Lib/distutils/command/bdist.py
@@ -52,8 +52,7 @@ class bdist(Command):
     # This won't do in reality: will need to distinguish RPM-ish Linux,
     # Debian-ish Linux, Solaris, FreeBSD, ..., Windows, Mac OS.
     default_format = {'posix': 'gztar',
-                      'nt': 'zip',
-                      'os2': 'zip'}
+                      'nt': 'zip'}
 
     # Establish the preferred order (for the --help-formats option).
     format_commands = ['rpm', 'gztar', 'bztar', 'ztar', 'tar',
diff --git a/Lib/distutils/command/bdist_dumb.py b/Lib/distutils/command/bdist_dumb.py
index 1ab09d1..eefdfea 100644
--- a/Lib/distutils/command/bdist_dumb.py
+++ b/Lib/distutils/command/bdist_dumb.py
@@ -38,8 +38,7 @@ class bdist_dumb(Command):
     boolean_options = ['keep-temp', 'skip-build', 'relative']
 
     default_format = { 'posix': 'gztar',
-                       'nt': 'zip',
-                       'os2': 'zip' }
+                       'nt': 'zip' }
 
     def initialize_options(self):
         self.bdist_dir = None
@@ -85,11 +84,6 @@ class bdist_dumb(Command):
         archive_basename = "%s.%s" % (self.distribution.get_fullname(),
                                       self.plat_name)
 
-        # OS/2 objects to any ":" characters in a filename (such as when
-        # a timestamp is used in a version) so change them to hyphens.
-        if os.name == "os2":
-            archive_basename = archive_basename.replace(":", "-")
-
         pseudoinstall_root = os.path.join(self.dist_dir, archive_basename)
         if not self.relative:
             archive_root = self.bdist_dir
diff --git a/Lib/distutils/command/build_ext.py b/Lib/distutils/command/build_ext.py
index b1d951e..f7c71b3 100644
--- a/Lib/distutils/command/build_ext.py
+++ b/Lib/distutils/command/build_ext.py
@@ -230,11 +230,6 @@ class build_ext(Command):
                 self.library_dirs.append(os.path.join(sys.exec_prefix,
                                          'PC', 'VC6'))
 
-        # OS/2 (EMX) doesn't support Debug vs Release builds, but has the
-        # import libraries in its "Config" subdirectory
-        if os.name == 'os2':
-            self.library_dirs.append(os.path.join(sys.exec_prefix, 'Config'))
-
         # for extensions under Cygwin and AtheOS Python's library directory must be
         # appended to library_dirs
         if sys.platform[:6] == 'cygwin' or sys.platform[:6] == 'atheos':
@@ -620,9 +615,6 @@ class build_ext(Command):
                     return fn
             else:
                 return "swig.exe"
-        elif os.name == "os2":
-            # assume swig available in the PATH.
-            return "swig.exe"
         else:
             raise DistutilsPlatformError(
                   "I don't know how to find (much less run) SWIG "
@@ -673,9 +665,6 @@ class build_ext(Command):
         """
         from distutils.sysconfig import get_config_var
         ext_path = ext_name.split('.')
-        # OS/2 has an 8 character module (extension) limit :-(
-        if os.name == "os2":
-            ext_path[len(ext_path) - 1] = ext_path[len(ext_path) - 1][:8]
         # extensions in debug_mode are named 'module_d.pyd' under windows
         so_ext = get_config_var('SO')
         if os.name == 'nt' and self.debug:
@@ -696,7 +685,7 @@ class build_ext(Command):
     def get_libraries(self, ext):
         """Return the list of libraries to link against when building a
         shared extension.  On most platforms, this is just 'ext.libraries';
-        on Windows and OS/2, we add the Python library (eg. python20.dll).
+        on Windows, we add the Python library (eg. python20.dll).
         """
         # The python library is always needed on Windows.  For MSVC, this
         # is redundant, since the library is mentioned in a pragma in
@@ -716,19 +705,6 @@ class build_ext(Command):
                 return ext.libraries + [pythonlib]
             else:
                 return ext.libraries
-        elif sys.platform == "os2emx":
-            # EMX/GCC requires the python library explicitly, and I
-            # believe VACPP does as well (though not confirmed) - AIM Apr01
-            template = "python%d%d"
-            # debug versions of the main DLL aren't supported, at least
-            # not at this time - AIM Apr01
-            #if self.debug:
-            #    template = template + '_d'
-            pythonlib = (template %
-                   (sys.hexversion >> 24, (sys.hexversion >> 16) & 0xff))
-            # don't extend ext.libraries, it may be shared with other
-            # extensions, it is a reference to the original list
-            return ext.libraries + [pythonlib]
         elif sys.platform[:6] == "cygwin":
             template = "python%d.%d"
             pythonlib = (template %
diff --git a/Lib/distutils/command/build_scripts.py b/Lib/distutils/command/build_scripts.py
index 4b5b22e..90a8380 100644
--- a/Lib/distutils/command/build_scripts.py
+++ b/Lib/distutils/command/build_scripts.py
@@ -74,7 +74,7 @@ class build_scripts(Command):
             # script.
             try:
                 f = open(script, "rb")
-            except IOError:
+            except OSError:
                 if not self.dry_run:
                     raise
                 f = None
diff --git a/Lib/distutils/command/install.py b/Lib/distutils/command/install.py
index 0161898..04326a1 100644
--- a/Lib/distutils/command/install.py
+++ b/Lib/distutils/command/install.py
@@ -58,13 +58,6 @@ INSTALL_SCHEMES = {
         'data'   : '$base',
         },
     'nt': WINDOWS_SCHEME,
-    'os2': {
-        'purelib': '$base/Lib/site-packages',
-        'platlib': '$base/Lib/site-packages',
-        'headers': '$base/Include/$dist_name',
-        'scripts': '$base/Scripts',
-        'data'   : '$base',
-        },
     }
 
 # user site schemes
@@ -86,14 +79,6 @@ if HAS_USER_SITE:
         'data'   : '$userbase',
         }
 
-    INSTALL_SCHEMES['os2_home'] = {
-        'purelib': '$usersite',
-        'platlib': '$usersite',
-        'headers': '$userbase/include/python$py_version_short/$dist_name',
-        'scripts': '$userbase/bin',
-        'data'   : '$userbase',
-        }
-
 # The keys to an installation scheme; if any new types of files are to be
 # installed, be sure to add an entry to every installation scheme above,
 # and to SCHEME_KEYS here.
diff --git a/Lib/distutils/command/upload.py b/Lib/distutils/command/upload.py
index 8b36851..88990b2 100644
--- a/Lib/distutils/command/upload.py
+++ b/Lib/distutils/command/upload.py
@@ -186,7 +186,7 @@ class upload(PyPIRCCommand):
             http.putheader('Authorization', auth)
             http.endheaders()
             http.send(body)
-        except socket.error as e:
+        except OSError as e:
             self.announce(str(e), log.ERROR)
             return
 
diff --git a/Lib/distutils/core.py b/Lib/distutils/core.py
index 260332a..91e5132 100644
--- a/Lib/distutils/core.py
+++ b/Lib/distutils/core.py
@@ -148,7 +148,7 @@ def setup (**attrs):
             dist.run_commands()
         except KeyboardInterrupt:
             raise SystemExit("interrupted")
-        except (IOError, os.error) as exc:
+        except OSError as exc:
             error = grok_environment_error(exc)
 
             if DEBUG:
diff --git a/Lib/distutils/cygwinccompiler.py b/Lib/distutils/cygwinccompiler.py
index 0bdd539..0c23ab1 100644
--- a/Lib/distutils/cygwinccompiler.py
+++ b/Lib/distutils/cygwinccompiler.py
@@ -359,7 +359,7 @@ def check_config_h():
                 return CONFIG_H_NOTOK, "'%s' does not mention '__GNUC__'" % fn
         finally:
             config_h.close()
-    except IOError as exc:
+    except OSError as exc:
         return (CONFIG_H_UNCERTAIN,
                 "couldn't read '%s': %s" % (fn, exc.strerror))
 
diff --git a/Lib/distutils/dir_util.py b/Lib/distutils/dir_util.py
index 2826ff8..2b35aa3 100644
--- a/Lib/distutils/dir_util.py
+++ b/Lib/distutils/dir_util.py
@@ -124,7 +124,7 @@ def copy_tree(src, dst, preserve_mode=1, preserve_times=1,
               "cannot copy tree '%s': not a directory" % src)
     try:
         names = os.listdir(src)
-    except os.error as e:
+    except OSError as e:
         (errno, errstr) = e
         if dry_run:
             names = []
@@ -198,7 +198,7 @@ def remove_tree(directory, verbose=1, dry_run=0):
             abspath = os.path.abspath(cmd[1])
             if abspath in _path_created:
                 del _path_created[abspath]
-        except (IOError, OSError) as exc:
+        except OSError as exc:
             log.warn(grok_environment_error(
                     exc, "error removing %s: " % directory))
 
diff --git a/Lib/distutils/emxccompiler.py b/Lib/distutils/emxccompiler.py
deleted file mode 100644
index 3675f8d..0000000
--- a/Lib/distutils/emxccompiler.py
+++ /dev/null
@@ -1,315 +0,0 @@
-"""distutils.emxccompiler
-
-Provides the EMXCCompiler class, a subclass of UnixCCompiler that
-handles the EMX port of the GNU C compiler to OS/2.
-"""
-
-# issues:
-#
-# * OS/2 insists that DLLs can have names no longer than 8 characters
-#   We put export_symbols in a def-file, as though the DLL can have
-#   an arbitrary length name, but truncate the output filename.
-#
-# * only use OMF objects and use LINK386 as the linker (-Zomf)
-#
-# * always build for multithreading (-Zmt) as the accompanying OS/2 port
-#   of Python is only distributed with threads enabled.
-#
-# tested configurations:
-#
-# * EMX gcc 2.81/EMX 0.9d fix03
-
-import os,sys,copy
-from distutils.ccompiler import gen_preprocess_options, gen_lib_options
-from distutils.unixccompiler import UnixCCompiler
-from distutils.file_util import write_file
-from distutils.errors import DistutilsExecError, CompileError, UnknownFileError
-from distutils import log
-
-class EMXCCompiler (UnixCCompiler):
-
-    compiler_type = 'emx'
-    obj_extension = ".obj"
-    static_lib_extension = ".lib"
-    shared_lib_extension = ".dll"
-    static_lib_format = "%s%s"
-    shared_lib_format = "%s%s"
-    res_extension = ".res"      # compiled resource file
-    exe_extension = ".exe"
-
-    def __init__ (self,
-                  verbose=0,
-                  dry_run=0,
-                  force=0):
-
-        UnixCCompiler.__init__ (self, verbose, dry_run, force)
-
-        (status, details) = check_config_h()
-        self.debug_print("Python's GCC status: %s (details: %s)" %
-                         (status, details))
-        if status is not CONFIG_H_OK:
-            self.warn(
-                "Python's pyconfig.h doesn't seem to support your compiler.  " +
-                ("Reason: %s." % details) +
-                "Compiling may fail because of undefined preprocessor macros.")
-
-        (self.gcc_version, self.ld_version) = \
-            get_versions()
-        self.debug_print(self.compiler_type + ": gcc %s, ld %s\n" %
-                         (self.gcc_version,
-                          self.ld_version) )
-
-        # Hard-code GCC because that's what this is all about.
-        # XXX optimization, warnings etc. should be customizable.
-        self.set_executables(compiler='gcc -Zomf -Zmt -O3 -fomit-frame-pointer -mprobe -Wall',
-                             compiler_so='gcc -Zomf -Zmt -O3 -fomit-frame-pointer -mprobe -Wall',
-                             linker_exe='gcc -Zomf -Zmt -Zcrtdll',
-                             linker_so='gcc -Zomf -Zmt -Zcrtdll -Zdll')
-
-        # want the gcc library statically linked (so that we don't have
-        # to distribute a version dependent on the compiler we have)
-        self.dll_libraries=["gcc"]
-
-    # __init__ ()
-
-    def _compile(self, obj, src, ext, cc_args, extra_postargs, pp_opts):
-        if ext == '.rc':
-            # gcc requires '.rc' compiled to binary ('.res') files !!!
-            try:
-                self.spawn(["rc", "-r", src])
-            except DistutilsExecError as msg:
-                raise CompileError(msg)
-        else: # for other files use the C-compiler
-            try:
-                self.spawn(self.compiler_so + cc_args + [src, '-o', obj] +
-                           extra_postargs)
-            except DistutilsExecError as msg:
-                raise CompileError(msg)
-
-    def link (self,
-              target_desc,
-              objects,
-              output_filename,
-              output_dir=None,
-              libraries=None,
-              library_dirs=None,
-              runtime_library_dirs=None,
-              export_symbols=None,
-              debug=0,
-              extra_preargs=None,
-              extra_postargs=None,
-              build_temp=None,
-              target_lang=None):
-
-        # use separate copies, so we can modify the lists
-        extra_preargs = copy.copy(extra_preargs or [])
-        libraries = copy.copy(libraries or [])
-        objects = copy.copy(objects or [])
-
-        # Additional libraries
-        libraries.extend(self.dll_libraries)
-
-        # handle export symbols by creating a def-file
-        # with executables this only works with gcc/ld as linker
-        if ((export_symbols is not None) and
-            (target_desc != self.EXECUTABLE)):
-            # (The linker doesn't do anything if output is up-to-date.
-            # So it would probably better to check if we really need this,
-            # but for this we had to insert some unchanged parts of
-            # UnixCCompiler, and this is not what we want.)
-
-            # we want to put some files in the same directory as the
-            # object files are, build_temp doesn't help much
-            # where are the object files
-            temp_dir = os.path.dirname(objects[0])
-            # name of dll to give the helper files the same base name
-            (dll_name, dll_extension) = os.path.splitext(
-                os.path.basename(output_filename))
-
-            # generate the filenames for these files
-            def_file = os.path.join(temp_dir, dll_name + ".def")
-
-            # Generate .def file
-            contents = [
-                "LIBRARY %s INITINSTANCE TERMINSTANCE" % \
-                os.path.splitext(os.path.basename(output_filename))[0],
-                "DATA MULTIPLE NONSHARED",
-                "EXPORTS"]
-            for sym in export_symbols:
-                contents.append('  "%s"' % sym)
-            self.execute(write_file, (def_file, contents),
-                         "writing %s" % def_file)
-
-            # next add options for def-file and to creating import libraries
-            # for gcc/ld the def-file is specified as any other object files
-            objects.append(def_file)
-
-        #end: if ((export_symbols is not None) and
-        #        (target_desc != self.EXECUTABLE or self.linker_dll == "gcc")):
-
-        # who wants symbols and a many times larger output file
-        # should explicitly switch the debug mode on
-        # otherwise we let dllwrap/ld strip the output file
-        # (On my machine: 10KB < stripped_file < ??100KB
-        #   unstripped_file = stripped_file + XXX KB
-        #  ( XXX=254 for a typical python extension))
-        if not debug:
-            extra_preargs.append("-s")
-
-        UnixCCompiler.link(self,
-                           target_desc,
-                           objects,
-                           output_filename,
-                           output_dir,
-                           libraries,
-                           library_dirs,
-                           runtime_library_dirs,
-                           None, # export_symbols, we do this in our def-file
-                           debug,
-                           extra_preargs,
-                           extra_postargs,
-                           build_temp,
-                           target_lang)
-
-    # link ()
-
-    # -- Miscellaneous methods -----------------------------------------
-
-    # override the object_filenames method from CCompiler to
-    # support rc and res-files
-    def object_filenames (self,
-                          source_filenames,
-                          strip_dir=0,
-                          output_dir=''):
-        if output_dir is None: output_dir = ''
-        obj_names = []
-        for src_name in source_filenames:
-            # use normcase to make sure '.rc' is really '.rc' and not '.RC'
-            (base, ext) = os.path.splitext (os.path.normcase(src_name))
-            if ext not in (self.src_extensions + ['.rc']):
-                raise UnknownFileError("unknown file type '%s' (from '%s')" % \
-                      (ext, src_name))
-            if strip_dir:
-                base = os.path.basename (base)
-            if ext == '.rc':
-                # these need to be compiled to object files
-                obj_names.append (os.path.join (output_dir,
-                                            base + self.res_extension))
-            else:
-                obj_names.append (os.path.join (output_dir,
-                                            base + self.obj_extension))
-        return obj_names
-
-    # object_filenames ()
-
-    # override the find_library_file method from UnixCCompiler
-    # to deal with file naming/searching differences
-    def find_library_file(self, dirs, lib, debug=0):
-        shortlib = '%s.lib' % lib
-        longlib = 'lib%s.lib' % lib    # this form very rare
-
-        # get EMX's default library directory search path
-        try:
-            emx_dirs = os.environ['LIBRARY_PATH'].split(';')
-        except KeyError:
-            emx_dirs = []
-
-        for dir in dirs + emx_dirs:
-            shortlibp = os.path.join(dir, shortlib)
-            longlibp = os.path.join(dir, longlib)
-            if os.path.exists(shortlibp):
-                return shortlibp
-            elif os.path.exists(longlibp):
-                return longlibp
-
-        # Oops, didn't find it in *any* of 'dirs'
-        return None
-
-# class EMXCCompiler
-
-
-# Because these compilers aren't configured in Python's pyconfig.h file by
-# default, we should at least warn the user if he is using a unmodified
-# version.
-
-CONFIG_H_OK = "ok"
-CONFIG_H_NOTOK = "not ok"
-CONFIG_H_UNCERTAIN = "uncertain"
-
-def check_config_h():
-
-    """Check if the current Python installation (specifically, pyconfig.h)
-    appears amenable to building extensions with GCC.  Returns a tuple
-    (status, details), where 'status' is one of the following constants:
-      CONFIG_H_OK
-        all is well, go ahead and compile
-      CONFIG_H_NOTOK
-        doesn't look good
-      CONFIG_H_UNCERTAIN
-        not sure -- unable to read pyconfig.h
-    'details' is a human-readable string explaining the situation.
-
-    Note there are two ways to conclude "OK": either 'sys.version' contains
-    the string "GCC" (implying that this Python was built with GCC), or the
-    installed "pyconfig.h" contains the string "__GNUC__".
-    """
-
-    # XXX since this function also checks sys.version, it's not strictly a
-    # "pyconfig.h" check -- should probably be renamed...
-
-    from distutils import sysconfig
-    # if sys.version contains GCC then python was compiled with
-    # GCC, and the pyconfig.h file should be OK
-    if sys.version.find("GCC") >= 0:
-        return (CONFIG_H_OK, "sys.version mentions 'GCC'")
-
-    fn = sysconfig.get_config_h_filename()
-    try:
-        # It would probably better to read single lines to search.
-        # But we do this only once, and it is fast enough
-        f = open(fn)
-        try:
-            s = f.read()
-        finally:
-            f.close()
-
-    except IOError as exc:
-        # if we can't read this file, we cannot say it is wrong
-        # the compiler will complain later about this file as missing
-        return (CONFIG_H_UNCERTAIN,
-                "couldn't read '%s': %s" % (fn, exc.strerror))
-
-    else:
-        # "pyconfig.h" contains an "#ifdef __GNUC__" or something similar
-        if s.find("__GNUC__") >= 0:
-            return (CONFIG_H_OK, "'%s' mentions '__GNUC__'" % fn)
-        else:
-            return (CONFIG_H_NOTOK, "'%s' does not mention '__GNUC__'" % fn)
-
-
-def get_versions():
-    """ Try to find out the versions of gcc and ld.
-        If not possible it returns None for it.
-    """
-    from distutils.version import StrictVersion
-    from distutils.spawn import find_executable
-    import re
-
-    gcc_exe = find_executable('gcc')
-    if gcc_exe:
-        out = os.popen(gcc_exe + ' -dumpversion','r')
-        try:
-            out_string = out.read()
-        finally:
-            out.close()
-        result = re.search('(\d+\.\d+\.\d+)', out_string, re.ASCII)
-        if result:
-            gcc_version = StrictVersion(result.group(1))
-        else:
-            gcc_version = None
-    else:
-        gcc_version = None
-    # EMX ld has no way of reporting version number, and we use GCC
-    # anyway - so we can link OMF DLLs
-    ld_version = None
-    return (gcc_version, ld_version)
diff --git a/Lib/distutils/errors.py b/Lib/distutils/errors.py
index eb13c98..8b93059 100644
--- a/Lib/distutils/errors.py
+++ b/Lib/distutils/errors.py
@@ -35,8 +35,8 @@ class DistutilsArgError (DistutilsError):
 
 class DistutilsFileError (DistutilsError):
     """Any problems in the filesystem: expected file not found, etc.
-    Typically this is for problems that we detect before IOError or
-    OSError could be raised."""
+    Typically this is for problems that we detect before OSError
+    could be raised."""
     pass
 
 class DistutilsOptionError (DistutilsError):
diff --git a/Lib/distutils/file_util.py b/Lib/distutils/file_util.py
index 9bdd14e..f6ed290 100644
--- a/Lib/distutils/file_util.py
+++ b/Lib/distutils/file_util.py
@@ -27,26 +27,26 @@ def _copy_file_contents(src, dst, buffer_size=16*1024):
     try:
         try:
             fsrc = open(src, 'rb')
-        except os.error as e:
+        except OSError as e:
             raise DistutilsFileError("could not open '%s': %s" % (src, e.strerror))
 
         if os.path.exists(dst):
             try:
                 os.unlink(dst)
-            except os.error as e:
+            except OSError as e:
                 raise DistutilsFileError(
                       "could not delete '%s': %s" % (dst, e.strerror))
 
         try:
             fdst = open(dst, 'wb')
-        except os.error as e:
+        except OSError as e:
             raise DistutilsFileError(
                   "could not create '%s': %s" % (dst, e.strerror))
 
         while True:
             try:
                 buf = fsrc.read(buffer_size)
-            except os.error as e:
+            except OSError as e:
                 raise DistutilsFileError(
                       "could not read from '%s': %s" % (src, e.strerror))
 
@@ -55,7 +55,7 @@ def _copy_file_contents(src, dst, buffer_size=16*1024):
 
             try:
                 fdst.write(buf)
-            except os.error as e:
+            except OSError as e:
                 raise DistutilsFileError(
                       "could not write to '%s': %s" % (dst, e.strerror))
     finally:
@@ -193,7 +193,7 @@ def move_file (src, dst,
     copy_it = False
     try:
         os.rename(src, dst)
-    except os.error as e:
+    except OSError as e:
         (num, msg) = e
         if num == errno.EXDEV:
             copy_it = True
@@ -205,11 +205,11 @@ def move_file (src, dst,
         copy_file(src, dst, verbose=verbose)
         try:
             os.unlink(src)
-        except os.error as e:
+        except OSError as e:
             (num, msg) = e
             try:
                 os.unlink(dst)
-            except os.error:
+            except OSError:
                 pass
             raise DistutilsFileError(
                   "couldn't move '%s' to '%s' by copy/delete: "
diff --git a/Lib/distutils/msvc9compiler.py b/Lib/distutils/msvc9compiler.py
index b3f6ce1..9688f20 100644
--- a/Lib/distutils/msvc9compiler.py
+++ b/Lib/distutils/msvc9compiler.py
@@ -729,7 +729,7 @@ class MSVCCompiler(CCompiler) :
                 return manifest_file
             finally:
                 manifest_f.close()
-        except IOError:
+        except OSError:
             pass
 
     # -- Miscellaneous methods -----------------------------------------
diff --git a/Lib/distutils/spawn.py b/Lib/distutils/spawn.py
index f58c55f..b1c5a44 100644
--- a/Lib/distutils/spawn.py
+++ b/Lib/distutils/spawn.py
@@ -32,8 +32,6 @@ def spawn(cmd, search_path=1, verbose=0, dry_run=0):
         _spawn_posix(cmd, search_path, dry_run=dry_run)
     elif os.name == 'nt':
         _spawn_nt(cmd, search_path, dry_run=dry_run)
-    elif os.name == 'os2':
-        _spawn_os2(cmd, search_path, dry_run=dry_run)
     else:
         raise DistutilsPlatformError(
               "don't know how to spawn programs on platform '%s'" % os.name)
@@ -74,26 +72,6 @@ def _spawn_nt(cmd, search_path=1, verbose=0, dry_run=0):
             raise DistutilsExecError(
                   "command '%s' failed with exit status %d" % (cmd[0], rc))
 
-def _spawn_os2(cmd, search_path=1, verbose=0, dry_run=0):
-    executable = cmd[0]
-    if search_path:
-        # either we find one or it stays the same
-        executable = find_executable(executable) or executable
-    log.info(' '.join([executable] + cmd[1:]))
-    if not dry_run:
-        # spawnv for OS/2 EMX requires a full path to the .exe
-        try:
-            rc = os.spawnv(os.P_WAIT, executable, cmd)
-        except OSError as exc:
-            # this seems to happen when the command isn't found
-            raise DistutilsExecError(
-                  "command '%s' failed: %s" % (cmd[0], exc.args[-1]))
-        if rc != 0:
-            # and this reflects the command running but failing
-            log.debug("command '%s' failed with exit status %d" % (cmd[0], rc))
-            raise DistutilsExecError(
-                  "command '%s' failed with exit status %d" % (cmd[0], rc))
-
 if sys.platform == 'darwin':
     from distutils import sysconfig
     _cfg_target = None
@@ -180,7 +158,7 @@ def find_executable(executable, path=None):
     paths = path.split(os.pathsep)
     base, ext = os.path.splitext(executable)
 
-    if (sys.platform == 'win32' or os.name == 'os2') and (ext != '.exe'):
+    if (sys.platform == 'win32') and (ext != '.exe'):
         executable = executable + '.exe'
 
     if not os.path.isfile(executable):
diff --git a/Lib/distutils/sysconfig.py b/Lib/distutils/sysconfig.py
index d125e0b..71492f3 100644
--- a/Lib/distutils/sysconfig.py
+++ b/Lib/distutils/sysconfig.py
@@ -114,8 +114,6 @@ def get_python_inc(plat_specific=0, prefix=None):
         return os.path.join(prefix, "include", python_dir)
     elif os.name == "nt":
         return os.path.join(prefix, "include")
-    elif os.name == "os2":
-        return os.path.join(prefix, "Include")
     else:
         raise DistutilsPlatformError(
             "I don't know where Python installs its C header files "
@@ -157,11 +155,6 @@ def get_python_lib(plat_specific=0, standard_lib=0, prefix=None):
                 return prefix
             else:
                 return os.path.join(prefix, "Lib", "site-packages")
-    elif os.name == "os2":
-        if standard_lib:
-            return os.path.join(prefix, "Lib")
-        else:
-            return os.path.join(prefix, "Lib", "site-packages")
     else:
         raise DistutilsPlatformError(
             "I don't know where Python installs its library "
@@ -436,7 +429,7 @@ def _init_posix():
     try:
         filename = get_makefile_filename()
         parse_makefile(filename, g)
-    except IOError as msg:
+    except OSError as msg:
         my_msg = "invalid Python installation: unable to open %s" % filename
         if hasattr(msg, "strerror"):
             my_msg = my_msg + " (%s)" % msg.strerror
@@ -448,7 +441,7 @@ def _init_posix():
         filename = get_config_h_filename()
         with open(filename) as file:
             parse_config_h(file, g)
-    except IOError as msg:
+    except OSError as msg:
         my_msg = "invalid Python installation: unable to open %s" % filename
         if hasattr(msg, "strerror"):
             my_msg = my_msg + " (%s)" % msg.strerror
@@ -495,23 +488,6 @@ def _init_nt():
     _config_vars = g
 
 
-def _init_os2():
-    """Initialize the module as appropriate for OS/2"""
-    g = {}
-    # set basic install directories
-    g['LIBDEST'] = get_python_lib(plat_specific=0, standard_lib=1)
-    g['BINLIBDEST'] = get_python_lib(plat_specific=1, standard_lib=1)
-
-    # XXX hmmm.. a normal install puts include files here
-    g['INCLUDEPY'] = get_python_inc(plat_specific=0)
-
-    g['SO'] = '.pyd'
-    g['EXE'] = ".exe"
-
-    global _config_vars
-    _config_vars = g
-
-
 def get_config_vars(*args):
     """With no arguments, return a dictionary of all configuration
     variables relevant for the current platform.  Generally this includes
diff --git a/Lib/distutils/tests/test_bdist_dumb.py b/Lib/distutils/tests/test_bdist_dumb.py
index 1037d82..761051c 100644
--- a/Lib/distutils/tests/test_bdist_dumb.py
+++ b/Lib/distutils/tests/test_bdist_dumb.py
@@ -75,8 +75,6 @@ class BuildDumbTestCase(support.TempdirManager,
         # see what we have
         dist_created = os.listdir(os.path.join(pkg_dir, 'dist'))
         base = "%s.%s.zip" % (dist.get_fullname(), cmd.plat_name)
-        if os.name == 'os2':
-            base = base.replace(':', '-')
 
         self.assertEqual(dist_created, [base])
 
diff --git a/Lib/distutils/tests/test_install.py b/Lib/distutils/tests/test_install.py
index cb2e1f2..47d630c 100644
--- a/Lib/distutils/tests/test_install.py
+++ b/Lib/distutils/tests/test_install.py
@@ -94,7 +94,7 @@ class InstallTestCase(support.TempdirManager,
 
         self.addCleanup(cleanup)
 
-        for key in ('nt_user', 'unix_user', 'os2_home'):
+        for key in ('nt_user', 'unix_user'):
             self.assertIn(key, INSTALL_SCHEMES)
 
         dist = Distribution({'name': 'xx'})
diff --git a/Lib/distutils/tests/test_util.py b/Lib/distutils/tests/test_util.py
index eac9b51..b73cfe9 100644
--- a/Lib/distutils/tests/test_util.py
+++ b/Lib/distutils/tests/test_util.py
@@ -236,7 +236,7 @@ class UtilTestCase(support.EnvironGuard, unittest.TestCase):
         self.assertRaises(DistutilsPlatformError,
                           change_root, 'c:\\root', 'its\\here')
 
-        # XXX platforms to be covered: os2, mac
+        # XXX platforms to be covered: mac
 
     def test_check_environ(self):
         util._environ_checked = 0
diff --git a/Lib/distutils/util.py b/Lib/distutils/util.py
index 67d8166..a2f9544 100644
--- a/Lib/distutils/util.py
+++ b/Lib/distutils/util.py
@@ -154,12 +154,6 @@ def change_root (new_root, pathname):
             path = path[1:]
         return os.path.join(new_root, path)
 
-    elif os.name == 'os2':
-        (drive, path) = os.path.splitdrive(pathname)
-        if path[0] == os.sep:
-            path = path[1:]
-        return os.path.join(new_root, path)
-
     else:
         raise DistutilsPlatformError("nothing known about platform '%s'" % os.name)
 
@@ -213,8 +207,8 @@ def subst_vars (s, local_vars):
 
 
 def grok_environment_error (exc, prefix="error: "):
-    """Generate a useful error message from an EnvironmentError (IOError or
-    OSError) exception object.  Handles Python 1.5.1 and 1.5.2 styles, and
+    """Generate a useful error message from an OSError
+    exception object.  Handles Python 1.5.1 and 1.5.2 styles, and
     does what it can to deal with exception objects that don't have a
     filename (which happens when the error is due to a two-file operation,
     such as 'rename()' or 'link()'.  Returns the error message as a string
diff --git a/Lib/doctest.py b/Lib/doctest.py
index 3af05fb..16a732d 100644
--- a/Lib/doctest.py
+++ b/Lib/doctest.py
@@ -62,6 +62,7 @@ __all__ = [
     'REPORT_NDIFF',
     'REPORT_ONLY_FIRST_FAILURE',
     'REPORTING_FLAGS',
+    'FAIL_FAST',
     # 1. Utility Functions
     # 2. Example & DocTest
     'Example',
@@ -150,11 +151,13 @@ REPORT_UDIFF = register_optionflag('REPORT_UDIFF')
 REPORT_CDIFF = register_optionflag('REPORT_CDIFF')
 REPORT_NDIFF = register_optionflag('REPORT_NDIFF')
 REPORT_ONLY_FIRST_FAILURE = register_optionflag('REPORT_ONLY_FIRST_FAILURE')
+FAIL_FAST = register_optionflag('FAIL_FAST')
 
 REPORTING_FLAGS = (REPORT_UDIFF |
                    REPORT_CDIFF |
                    REPORT_NDIFF |
-                   REPORT_ONLY_FIRST_FAILURE)
+                   REPORT_ONLY_FIRST_FAILURE |
+                   FAIL_FAST)
 
 # Special string markers for use in `want` strings:
 BLANKLINE_MARKER = '<BLANKLINE>'
@@ -1342,6 +1345,9 @@ class DocTestRunner:
             else:
                 assert False, ("unknown outcome", outcome)
 
+            if failures and self.optionflags & FAIL_FAST:
+                break
+
         # Restore the option flags (in case they were modified)
         self.optionflags = original_optionflags
 
diff --git a/Lib/email/_header_value_parser.py b/Lib/email/_header_value_parser.py
index 1924ed1..b596462 100644
--- a/Lib/email/_header_value_parser.py
+++ b/Lib/email/_header_value_parser.py
@@ -367,8 +367,7 @@ class TokenList(list):
                 yield (indent + '    !! invalid element in token '
                                         'list: {!r}'.format(token))
             else:
-                for line in token._pp(indent+'    '):
-                    yield line
+                yield from token._pp(indent+'    ')
         if self.defects:
             extra = ' Defects: {}'.format(self.defects)
         else:
diff --git a/Lib/email/iterators.py b/Lib/email/iterators.py
index 3adc4a0..b5502ee 100644
--- a/Lib/email/iterators.py
+++ b/Lib/email/iterators.py
@@ -26,8 +26,7 @@ def walk(self):
     yield self
     if self.is_multipart():
         for subpart in self.get_payload():
-            for subsubpart in subpart.walk():
-                yield subsubpart
+            yield from subpart.walk()
 
 
 
@@ -40,8 +39,7 @@ def body_line_iterator(msg, decode=False):
     for subpart in msg.walk():
         payload = subpart.get_payload(decode=decode)
         if isinstance(payload, str):
-            for line in StringIO(payload):
-                yield line
+            yield from StringIO(payload)
 
 
 def typed_subpart_iterator(msg, maintype='text', subtype=None):
diff --git a/Lib/filecmp.py b/Lib/filecmp.py
index f5cea1d..014c0d0 100644
--- a/Lib/filecmp.py
+++ b/Lib/filecmp.py
@@ -13,11 +13,15 @@ import os
 import stat
 from itertools import filterfalse
 
-__all__ = ["cmp", "dircmp", "cmpfiles"]
+__all__ = ['cmp', 'dircmp', 'cmpfiles', 'DEFAULT_IGNORES']
 
 _cache = {}
 BUFSIZE = 8*1024
 
+DEFAULT_IGNORES = [
+    'RCS', 'CVS', 'tags', '.git', '.hg', '.bzr', '_darcs', '__pycache__']
+
+
 def cmp(f1, f2, shallow=True):
     """Compare two files.
 
@@ -80,7 +84,7 @@ class dircmp:
     dircmp(a, b, ignore=None, hide=None)
       A and B are directories.
       IGNORE is a list of names to ignore,
-        defaults to ['RCS', 'CVS', 'tags'].
+        defaults to DEFAULT_IGNORES.
       HIDE is a list of names to hide,
         defaults to [os.curdir, os.pardir].
 
@@ -116,7 +120,7 @@ class dircmp:
         else:
             self.hide = hide
         if ignore is None:
-            self.ignore = ['RCS', 'CVS', 'tags'] # Names ignored in comparison
+            self.ignore = DEFAULT_IGNORES
         else:
             self.ignore = ignore
 
@@ -147,12 +151,12 @@ class dircmp:
             ok = 1
             try:
                 a_stat = os.stat(a_path)
-            except os.error as why:
+            except OSError as why:
                 # print('Can\'t stat', a_path, ':', why.args[1])
                 ok = 0
             try:
                 b_stat = os.stat(b_path)
-            except os.error as why:
+            except OSError as why:
                 # print('Can\'t stat', b_path, ':', why.args[1])
                 ok = 0
 
@@ -268,7 +272,7 @@ def cmpfiles(a, b, common, shallow=True):
 def _cmp(a, b, sh, abs=abs, cmp=cmp):
     try:
         return not abs(cmp(a, b, sh))
-    except os.error:
+    except OSError:
         return 2
 
 
diff --git a/Lib/fileinput.py b/Lib/fileinput.py
index dbbbb21..f9bb88a 100644
--- a/Lib/fileinput.py
+++ b/Lib/fileinput.py
@@ -30,7 +30,7 @@ pertaining to the last line read; nextfile() has no effect.
 
 All files are opened in text mode by default, you can override this by
 setting the mode parameter to input() or FileInput.__init__().
-If an I/O error occurs during opening or reading a file, the IOError
+If an I/O error occurs during opening or reading a file, the OSError
 exception is raised.
 
 If sys.stdin is used more than once, the second and further use will
@@ -324,9 +324,11 @@ class FileInput:
                 if self._inplace:
                     self._backupfilename = (
                         self._filename + (self._backup or ".bak"))
-                    try: os.unlink(self._backupfilename)
-                    except os.error: pass
-                    # The next few lines may raise IOError
+                    try:
+                        os.unlink(self._backupfilename)
+                    except OSError:
+                        pass
+                    # The next few lines may raise OSError
                     os.rename(self._filename, self._backupfilename)
                     self._file = open(self._backupfilename, self._mode)
                     try:
@@ -348,7 +350,7 @@ class FileInput:
                     self._savestdout = sys.stdout
                     sys.stdout = self._output
                 else:
-                    # This may raise IOError
+                    # This may raise OSError
                     if self._openhook:
                         self._file = self._openhook(self._filename, self._mode)
                     else:
diff --git a/Lib/fractions.py b/Lib/fractions.py
index 8be52d2..79e83ff 100644
--- a/Lib/fractions.py
+++ b/Lib/fractions.py
@@ -182,8 +182,10 @@ class Fraction(numbers.Rational):
         elif not isinstance(f, float):
             raise TypeError("%s.from_float() only takes floats, not %r (%s)" %
                             (cls.__name__, f, type(f).__name__))
-        if math.isnan(f) or math.isinf(f):
-            raise TypeError("Cannot convert %r to %s." % (f, cls.__name__))
+        if math.isnan(f):
+            raise ValueError("Cannot convert %r to %s." % (f, cls.__name__))
+        if math.isinf(f):
+            raise OverflowError("Cannot convert %r to %s." % (f, cls.__name__))
         return cls(*f.as_integer_ratio())
 
     @classmethod
@@ -196,9 +198,11 @@ class Fraction(numbers.Rational):
             raise TypeError(
                 "%s.from_decimal() only takes Decimals, not %r (%s)" %
                 (cls.__name__, dec, type(dec).__name__))
-        if not dec.is_finite():
-            # Catches infinities and nans.
-            raise TypeError("Cannot convert %s to %s." % (dec, cls.__name__))
+        if dec.is_infinite():
+            raise OverflowError(
+                "Cannot convert %s to %s." % (dec, cls.__name__))
+        if dec.is_nan():
+            raise ValueError("Cannot convert %s to %s." % (dec, cls.__name__))
         sign, digits, exp = dec.as_tuple()
         digits = int(''.join(map(str, digits)))
         if sign:
diff --git a/Lib/ftplib.py b/Lib/ftplib.py
index 5efae95..6aecd28 100644
--- a/Lib/ftplib.py
+++ b/Lib/ftplib.py
@@ -61,7 +61,7 @@ class error_proto(Error): pass          # response does not begin with [1-5]
 
 # All exceptions (hopefully) that may be raised here and that aren't
 # (always) programming errors on our side
-all_errors = (Error, IOError, EOFError)
+all_errors = (Error, OSError, EOFError)
 
 
 # Line terminators (we always output CRLF, but accept any of CRLF, CR, LF)
@@ -123,7 +123,7 @@ class FTP:
         if self.sock is not None:
             try:
                 self.quit()
-            except (socket.error, EOFError):
+            except (OSError, EOFError):
                 pass
             finally:
                 if self.sock is not None:
@@ -295,7 +295,7 @@ class FTP:
             try:
                 sock = socket.socket(af, socktype, proto)
                 sock.bind(sa)
-            except socket.error as _:
+            except OSError as _:
                 err = _
                 if sock:
                     sock.close()
@@ -306,8 +306,8 @@ class FTP:
             if err is not None:
                 raise err
             else:
-                raise socket.error("getaddrinfo returns an empty list")
-            raise socket.error(msg)
+                raise OSError("getaddrinfo returns an empty list")
+            raise OSError(msg)
         sock.listen(1)
         port = sock.getsockname()[1] # Get proper port
         host = self.sock.getsockname()[0] # Get proper host
@@ -826,7 +826,7 @@ else:
             return resp
 
     __all__.append('FTP_TLS')
-    all_errors = (Error, IOError, EOFError, ssl.SSLError)
+    all_errors = (Error, OSError, EOFError, ssl.SSLError)
 
 
 _150_re = None
@@ -958,7 +958,7 @@ class Netrc:
                 filename = os.path.join(os.environ["HOME"],
                                         ".netrc")
             else:
-                raise IOError("specify file to load or set $HOME")
+                raise OSError("specify file to load or set $HOME")
         self.__hosts = {}
         self.__macros = {}
         fp = open(filename, "r")
@@ -1074,7 +1074,7 @@ def test():
     userid = passwd = acct = ''
     try:
         netrc = Netrc(rcfile)
-    except IOError:
+    except OSError:
         if rcfile is not None:
             sys.stderr.write("Could not open account file"
                              " -- using anonymous login.")
diff --git a/Lib/functools.py b/Lib/functools.py
index 226a46e..60d2cf1 100644
--- a/Lib/functools.py
+++ b/Lib/functools.py
@@ -11,7 +11,10 @@
 __all__ = ['update_wrapper', 'wraps', 'WRAPPER_ASSIGNMENTS', 'WRAPPER_UPDATES',
            'total_ordering', 'cmp_to_key', 'lru_cache', 'reduce', 'partial']
 
-from _functools import partial, reduce
+try:
+    from _functools import reduce
+except ImportError:
+    pass
 from collections import namedtuple
 try:
     from _thread import allocate_lock as Lock
@@ -137,6 +140,29 @@ except ImportError:
 
 
 ################################################################################
+### partial() argument application
+################################################################################
+
+def partial(func, *args, **keywords):
+    """new function with partial application of the given arguments
+    and keywords.
+    """
+    def newfunc(*fargs, **fkeywords):
+        newkeywords = keywords.copy()
+        newkeywords.update(fkeywords)
+        return func(*(args + fargs), **newkeywords)
+    newfunc.func = func
+    newfunc.args = args
+    newfunc.keywords = keywords
+    return newfunc
+
+try:
+    from _functools import partial
+except ImportError:
+    pass
+
+
+################################################################################
 ### LRU Cache function decorator
 ################################################################################
 
diff --git a/Lib/genericpath.py b/Lib/genericpath.py
index 2174187..5292aa8 100644
--- a/Lib/genericpath.py
+++ b/Lib/genericpath.py
@@ -7,7 +7,8 @@ import os
 import stat
 
 __all__ = ['commonprefix', 'exists', 'getatime', 'getctime', 'getmtime',
-           'getsize', 'isdir', 'isfile']
+           'getsize', 'isdir', 'isfile', 'samefile', 'sameopenfile',
+           'samestat']
 
 
 # Does a path exist?
@@ -16,7 +17,7 @@ def exists(path):
     """Test whether a path exists.  Returns False for broken symbolic links"""
     try:
         os.stat(path)
-    except os.error:
+    except OSError:
         return False
     return True
 
@@ -27,7 +28,7 @@ def isfile(path):
     """Test whether a path is a regular file"""
     try:
         st = os.stat(path)
-    except os.error:
+    except OSError:
         return False
     return stat.S_ISREG(st.st_mode)
 
@@ -39,7 +40,7 @@ def isdir(s):
     """Return true if the pathname refers to an existing directory."""
     try:
         st = os.stat(s)
-    except os.error:
+    except OSError:
         return False
     return stat.S_ISDIR(st.st_mode)
 
@@ -75,6 +76,31 @@ def commonprefix(m):
             return s1[:i]
     return s1
 
+# Are two stat buffers (obtained from stat, fstat or lstat)
+# describing the same file?
+def samestat(s1, s2):
+    """Test whether two stat buffers reference the same file"""
+    return (s1.st_ino == s2.st_ino and
+            s1.st_dev == s2.st_dev)
+
+
+# Are two filenames really pointing to the same file?
+def samefile(f1, f2):
+    """Test whether two pathnames reference the same actual file"""
+    s1 = os.stat(f1)
+    s2 = os.stat(f2)
+    return samestat(s1, s2)
+
+
+# Are two open files really referencing the same file?
+# (Not necessarily the same file descriptor!)
+def sameopenfile(fp1, fp2):
+    """Test whether two open file objects reference the same file"""
+    s1 = os.fstat(fp1)
+    s2 = os.fstat(fp2)
+    return samestat(s1, s2)
+
+
 # Split a path in root and extension.
 # The extension is everything starting at the last dot in the last
 # pathname component; the root is everything before that.
diff --git a/Lib/getpass.py b/Lib/getpass.py
index 0044742..53689e9 100644
--- a/Lib/getpass.py
+++ b/Lib/getpass.py
@@ -47,7 +47,7 @@ def unix_getpass(prompt='Password: ', stream=None):
         input = tty
         if not stream:
             stream = tty
-    except EnvironmentError as e:
+    except OSError as e:
         # If that fails, see if stdin can be controlled.
         try:
             fd = sys.stdin.fileno()
diff --git a/Lib/gettext.py b/Lib/gettext.py
index e43f044..05d9c1e 100644
--- a/Lib/gettext.py
+++ b/Lib/gettext.py
@@ -244,7 +244,7 @@ class GNUTranslations(NullTranslations):
             version, msgcount, masteridx, transidx = unpack('>4I', buf[4:20])
             ii = '>II'
         else:
-            raise IOError(0, 'Bad magic number', filename)
+            raise OSError(0, 'Bad magic number', filename)
         # Now put all messages from the .mo file buffer into the catalog
         # dictionary.
         for i in range(0, msgcount):
@@ -256,7 +256,7 @@ class GNUTranslations(NullTranslations):
                 msg = buf[moff:mend]
                 tmsg = buf[toff:tend]
             else:
-                raise IOError(0, 'File is corrupt', filename)
+                raise OSError(0, 'File is corrupt', filename)
             # See if we're looking at GNU .mo conventions for metadata
             if mlen == 0:
                 # Catalog description
@@ -398,7 +398,7 @@ def translation(domain, localedir=None, languages=None,
     if not mofiles:
         if fallback:
             return NullTranslations()
-        raise IOError(ENOENT, 'No translation file found for domain', domain)
+        raise OSError(ENOENT, 'No translation file found for domain', domain)
     # Avoid opening, reading, and parsing the .mo file after it's been done
     # once.
     result = None
@@ -460,7 +460,7 @@ def dgettext(domain, message):
     try:
         t = translation(domain, _localedirs.get(domain, None),
                         codeset=_localecodesets.get(domain))
-    except IOError:
+    except OSError:
         return message
     return t.gettext(message)
 
@@ -468,7 +468,7 @@ def ldgettext(domain, message):
     try:
         t = translation(domain, _localedirs.get(domain, None),
                         codeset=_localecodesets.get(domain))
-    except IOError:
+    except OSError:
         return message
     return t.lgettext(message)
 
@@ -476,7 +476,7 @@ def dngettext(domain, msgid1, msgid2, n):
     try:
         t = translation(domain, _localedirs.get(domain, None),
                         codeset=_localecodesets.get(domain))
-    except IOError:
+    except OSError:
         if n == 1:
             return msgid1
         else:
@@ -487,7 +487,7 @@ def ldngettext(domain, msgid1, msgid2, n):
     try:
         t = translation(domain, _localedirs.get(domain, None),
                         codeset=_localecodesets.get(domain))
-    except IOError:
+    except OSError:
         if n == 1:
             return msgid1
         else:
diff --git a/Lib/glob.py b/Lib/glob.py
index f16e8e1..c9f8117 100644
--- a/Lib/glob.py
+++ b/Lib/glob.py
@@ -26,8 +26,7 @@ def iglob(pathname):
         return
     dirname, basename = os.path.split(pathname)
     if not dirname:
-        for name in glob1(None, basename):
-            yield name
+        yield from glob1(None, basename)
         return
     # `os.path.split()` returns the argument itself as a dirname if it is a
     # drive or UNC path.  Prevent an infinite recursion if a drive or UNC path
@@ -56,7 +55,7 @@ def glob1(dirname, pattern):
             dirname = os.curdir
     try:
         names = os.listdir(dirname)
-    except os.error:
+    except OSError:
         return []
     if not _ishidden(pattern):
         names = [x for x in names if not _ishidden(x)]
diff --git a/Lib/gzip.py b/Lib/gzip.py
index d7da02c..d5b5743 100644
--- a/Lib/gzip.py
+++ b/Lib/gzip.py
@@ -294,11 +294,11 @@ class GzipFile(io.BufferedIOBase):
             return False
 
         if magic != b'\037\213':
-            raise IOError('Not a gzipped file')
+            raise OSError('Not a gzipped file')
 
         method, flag, self.mtime = struct.unpack("<BBIxx", self._read_exact(8))
         if method != 8:
-            raise IOError('Unknown compression method')
+            raise OSError('Unknown compression method')
 
         if flag & FEXTRA:
             # Read & discard the extra field, if present
@@ -328,7 +328,7 @@ class GzipFile(io.BufferedIOBase):
         self._check_closed()
         if self.mode != WRITE:
             import errno
-            raise IOError(errno.EBADF, "write() on read-only GzipFile object")
+            raise OSError(errno.EBADF, "write() on read-only GzipFile object")
 
         if self.fileobj is None:
             raise ValueError("write() on closed GzipFile object")
@@ -349,7 +349,7 @@ class GzipFile(io.BufferedIOBase):
         self._check_closed()
         if self.mode != READ:
             import errno
-            raise IOError(errno.EBADF, "read() on write-only GzipFile object")
+            raise OSError(errno.EBADF, "read() on write-only GzipFile object")
 
         if self.extrasize <= 0 and self.fileobj is None:
             return b''
@@ -378,7 +378,7 @@ class GzipFile(io.BufferedIOBase):
         self._check_closed()
         if self.mode != READ:
             import errno
-            raise IOError(errno.EBADF, "read1() on write-only GzipFile object")
+            raise OSError(errno.EBADF, "read1() on write-only GzipFile object")
 
         if self.extrasize <= 0 and self.fileobj is None:
             return b''
@@ -399,7 +399,7 @@ class GzipFile(io.BufferedIOBase):
     def peek(self, n):
         if self.mode != READ:
             import errno
-            raise IOError(errno.EBADF, "peek() on write-only GzipFile object")
+            raise OSError(errno.EBADF, "peek() on write-only GzipFile object")
 
         # Do not return ridiculously small buffers, for one common idiom
         # is to call peek(1) and expect more bytes in return.
@@ -480,10 +480,10 @@ class GzipFile(io.BufferedIOBase):
         # stored is the true file size mod 2**32.
         crc32, isize = struct.unpack("<II", self._read_exact(8))
         if crc32 != self.crc:
-            raise IOError("CRC check failed %s != %s" % (hex(crc32),
+            raise OSError("CRC check failed %s != %s" % (hex(crc32),
                                                          hex(self.crc)))
         elif isize != (self.size & 0xffffffff):
-            raise IOError("Incorrect length of data produced")
+            raise OSError("Incorrect length of data produced")
 
         # Gzip files can be padded with zeroes and still have archives.
         # Consume all zero bytes and set the file position to the first
@@ -532,7 +532,7 @@ class GzipFile(io.BufferedIOBase):
         '''Return the uncompressed stream file position indicator to the
         beginning of the file'''
         if self.mode != READ:
-            raise IOError("Can't rewind in write mode")
+            raise OSError("Can't rewind in write mode")
         self.fileobj.seek(0)
         self._new_member = True
         self.extrabuf = b""
@@ -557,7 +557,7 @@ class GzipFile(io.BufferedIOBase):
                 raise ValueError('Seek from end not supported')
         if self.mode == WRITE:
             if offset < self.offset:
-                raise IOError('Negative seek in write mode')
+                raise OSError('Negative seek in write mode')
             count = offset - self.offset
             chunk = bytes(1024)
             for i in range(count // 1024):
diff --git a/Lib/hashlib.py b/Lib/hashlib.py
index 21454c7..a1bd8b2 100644
--- a/Lib/hashlib.py
+++ b/Lib/hashlib.py
@@ -54,7 +54,8 @@ More condensed:
 
 # This tuple and __get_builtin_constructor() must be modified if a new
 # always available algorithm is added.
-__always_supported = ('md5', 'sha1', 'sha224', 'sha256', 'sha384', 'sha512')
+__always_supported = ('md5', 'sha1', 'sha224', 'sha256', 'sha384', 'sha512',
+                      'sha3_224', 'sha3_256', 'sha3_384', 'sha3_512')
 
 algorithms_guaranteed = set(__always_supported)
 algorithms_available = set(__always_supported)
@@ -85,6 +86,18 @@ def __get_builtin_constructor(name):
                 return _sha512.sha512
             elif bs == '384':
                 return _sha512.sha384
+        elif name in {'sha3_224', 'sha3_256', 'sha3_384', 'sha3_512',
+                      'SHA3_224', 'SHA3_256', 'SHA3_384', 'SHA3_512'}:
+            import _sha3
+            bs = name[5:]
+            if bs == '224':
+                return _sha3.sha3_224
+            elif bs == '256':
+                return _sha3.sha3_256
+            elif bs == '384':
+                return _sha3.sha3_384
+            elif bs == '512':
+                return _sha3.sha3_512
     except ImportError:
         pass  # no extension module, this hash is unsupported.
 
diff --git a/Lib/http/client.py b/Lib/http/client.py
index 4663d43..ba7d6fc 100644
--- a/Lib/http/client.py
+++ b/Lib/http/client.py
@@ -728,6 +728,14 @@ class HTTPConnection:
     default_port = HTTP_PORT
     auto_open = 1
     debuglevel = 0
+    # TCP Maximum Segment Size (MSS) is determined by the TCP stack on
+    # a per-connection basis.  There is no simple and efficient
+    # platform independent mechanism for determining the MSS, so
+    # instead a reasonable estimate is chosen.  The getsockopt()
+    # interface using the TCP_MAXSEG parameter may be a suitable
+    # approach on some operating systems. A value of 16KiB is chosen
+    # as a reasonable estimate of the maximum MSS.
+    mss = 16384
 
     def __init__(self, host, port=None, strict=_strict_sentinel,
                  timeout=socket._GLOBAL_DEFAULT_TIMEOUT, source_address=None):
@@ -800,8 +808,8 @@ class HTTPConnection:
 
         if code != 200:
             self.close()
-            raise socket.error("Tunnel connection failed: %d %s" % (code,
-                                                                    message.strip()))
+            raise OSError("Tunnel connection failed: %d %s" % (code,
+                                                               message.strip()))
         while True:
             line = response.fp.readline(_MAXLINE + 1)
             if len(line) > _MAXLINE:
@@ -895,8 +903,11 @@ class HTTPConnection:
         del self._buffer[:]
         # If msg and message_body are sent in a single send() call,
         # it will avoid performance problems caused by the interaction
-        # between delayed ack and the Nagle algorithm.
-        if isinstance(message_body, bytes):
+        # between delayed ack and the Nagle algorithm. However,
+        # there is no performance gain if the message is larger
+        # than MSS (and there is a memory penalty for the message
+        # copy).
+        if isinstance(message_body, bytes) and len(message_body) < self.mss:
             msg += message_body
             message_body = None
         self.send(msg)
diff --git a/Lib/http/cookiejar.py b/Lib/http/cookiejar.py
index 901e762..7928e9b 100644
--- a/Lib/http/cookiejar.py
+++ b/Lib/http/cookiejar.py
@@ -1193,8 +1193,7 @@ def deepvalues(mapping):
             pass
         else:
             mapping = True
-            for subobj in deepvalues(obj):
-                yield subobj
+            yield from deepvalues(obj)
         if not mapping:
             yield obj
 
@@ -1731,8 +1730,8 @@ class CookieJar:
         return "<%s[%s]>" % (self.__class__, ", ".join(r))
 
 
-# derives from IOError for backwards-compatibility with Python 2.4.0
-class LoadError(IOError): pass
+# derives from OSError for backwards-compatibility with Python 2.4.0
+class LoadError(OSError): pass
 
 class FileCookieJar(CookieJar):
     """CookieJar that can be loaded from and saved to a file."""
@@ -1772,7 +1771,7 @@ class FileCookieJar(CookieJar):
                ignore_discard=False, ignore_expires=False):
         """Clear all cookies and reload cookies from a saved file.
 
-        Raises LoadError (or IOError) if reversion is not successful; the
+        Raises LoadError (or OSError) if reversion is not successful; the
         object's state will not be altered if this happens.
 
         """
@@ -1787,7 +1786,7 @@ class FileCookieJar(CookieJar):
             self._cookies = {}
             try:
                 self.load(filename, ignore_discard, ignore_expires)
-            except (LoadError, IOError):
+            except OSError:
                 self._cookies = old_state
                 raise
 
@@ -1938,8 +1937,7 @@ class LWPCookieJar(FileCookieJar):
                     if not ignore_expires and c.is_expired(now):
                         continue
                     self.set_cookie(c)
-
-        except IOError:
+        except OSError:
             raise
         except Exception:
             _warn_unhandled_exception()
@@ -2045,7 +2043,7 @@ class MozillaCookieJar(FileCookieJar):
                     continue
                 self.set_cookie(c)
 
-        except IOError:
+        except OSError:
             raise
         except Exception:
             _warn_unhandled_exception()
diff --git a/Lib/http/server.py b/Lib/http/server.py
index c4ac703..1873b13 100644
--- a/Lib/http/server.py
+++ b/Lib/http/server.py
@@ -425,12 +425,14 @@ class BaseHTTPRequestHandler(socketserver.StreamRequestHandler):
         # using _quote_html to prevent Cross Site Scripting attacks (see bug #1100201)
         content = (self.error_message_format %
                    {'code': code, 'message': _quote_html(message), 'explain': explain})
+        body = content.encode('UTF-8', 'replace')
         self.send_response(code, message)
         self.send_header("Content-Type", self.error_content_type)
         self.send_header('Connection', 'close')
+        self.send_header('Content-Length', int(len(body)))
         self.end_headers()
         if self.command != 'HEAD' and code >= 200 and code not in (204, 304):
-            self.wfile.write(content.encode('UTF-8', 'replace'))
+            self.wfile.write(body)
 
     def send_response(self, code, message=None):
         """Add the response header to the headers buffer and log the
@@ -709,7 +711,7 @@ class SimpleHTTPRequestHandler(BaseHTTPRequestHandler):
         ctype = self.guess_type(path)
         try:
             f = open(path, 'rb')
-        except IOError:
+        except OSError:
             self.send_error(404, "File not found")
             return None
         self.send_response(200)
@@ -730,7 +732,7 @@ class SimpleHTTPRequestHandler(BaseHTTPRequestHandler):
         """
         try:
             list = os.listdir(path)
-        except os.error:
+        except OSError:
             self.send_error(404, "No permission to list directory")
             return None
         list.sort(key=lambda a: a.lower())
@@ -1121,7 +1123,7 @@ class CGIHTTPRequestHandler(SimpleHTTPRequestHandler):
             try:
                 try:
                     os.setuid(nobody)
-                except os.error:
+                except OSError:
                     pass
                 os.dup2(self.rfile.fileno(), 0)
                 os.dup2(self.wfile.fileno(), 1)
diff --git a/Lib/idlelib/EditorWindow.py b/Lib/idlelib/EditorWindow.py
index 3397415..565cf36 100644
--- a/Lib/idlelib/EditorWindow.py
+++ b/Lib/idlelib/EditorWindow.py
@@ -542,7 +542,7 @@ class EditorWindow(object):
         if sys.platform[:3] == 'win':
             try:
                 os.startfile(self.help_url)
-            except WindowsError as why:
+            except OSError as why:
                 tkMessageBox.showerror(title='Document Start Failure',
                     message=str(why), parent=self.text)
         else:
@@ -852,7 +852,7 @@ class EditorWindow(object):
             if sys.platform[:3] == 'win':
                 try:
                     os.startfile(helpfile)
-                except WindowsError as why:
+                except OSError as why:
                     tkMessageBox.showerror(title='Document Start Failure',
                         message=str(why), parent=self.text)
             else:
@@ -886,7 +886,7 @@ class EditorWindow(object):
             with open(self.recent_files_path, 'w',
                         encoding='utf_8', errors='replace') as rf_file:
                 rf_file.writelines(rf_list)
-        except IOError as err:
+        except OSError as err:
             if not getattr(self.root, "recentfilelist_error_displayed", False):
                 self.root.recentfilelist_error_displayed = True
                 tkMessageBox.showerror(title='IDLE Error',
diff --git a/Lib/idlelib/FileList.py b/Lib/idlelib/FileList.py
index 37a337e..a9989a8 100644
--- a/Lib/idlelib/FileList.py
+++ b/Lib/idlelib/FileList.py
@@ -103,7 +103,7 @@ class FileList:
         if not os.path.isabs(filename):
             try:
                 pwd = os.getcwd()
-            except os.error:
+            except OSError:
                 pass
             else:
                 filename = os.path.join(pwd, filename)
diff --git a/Lib/idlelib/GrepDialog.py b/Lib/idlelib/GrepDialog.py
index 27fcc33..1d8d51b 100644
--- a/Lib/idlelib/GrepDialog.py
+++ b/Lib/idlelib/GrepDialog.py
@@ -82,7 +82,7 @@ class GrepDialog(SearchDialogBase):
         for fn in list:
             try:
                 f = open(fn, errors='replace')
-            except IOError as msg:
+            except OSError as msg:
                 print(msg)
                 continue
             lineno = 0
@@ -110,7 +110,7 @@ class GrepDialog(SearchDialogBase):
     def findfiles(self, dir, base, rec):
         try:
             names = os.listdir(dir or os.curdir)
-        except os.error as msg:
+        except OSError as msg:
             print(msg)
             return []
         list = []
diff --git a/Lib/idlelib/IOBinding.py b/Lib/idlelib/IOBinding.py
index 9fe0701..dda3634 100644
--- a/Lib/idlelib/IOBinding.py
+++ b/Lib/idlelib/IOBinding.py
@@ -213,7 +213,7 @@ class IOBinding:
             f.seek(0)
             bytes = f.read()
             f.close()
-        except IOError as msg:
+        except OSError as msg:
             tkMessageBox.showerror("I/O Error", str(msg), master=self.text)
             return False
         chars, converted = self._decode(two_lines, bytes)
@@ -378,7 +378,7 @@ class IOBinding:
             f.flush()
             f.close()
             return True
-        except IOError as msg:
+        except OSError as msg:
             tkMessageBox.showerror("I/O Error", str(msg),
                                    master=self.text)
             return False
@@ -504,7 +504,7 @@ class IOBinding:
         else:
             try:
                 pwd = os.getcwd()
-            except os.error:
+            except OSError:
                 pwd = ""
             return pwd, ""
 
diff --git a/Lib/idlelib/NEWS.txt b/Lib/idlelib/NEWS.txt
index f6e8917d..21752d7 100644
--- a/Lib/idlelib/NEWS.txt
+++ b/Lib/idlelib/NEWS.txt
@@ -1,6 +1,8 @@
-What's New in IDLE 3.3.1?
+What's New in IDLE 3.4.0?
 =========================
 
+- Issue #5066: Update IDLE docs. Patch by Todd Rovito.
+
 - Issue #16226: Fix IDLE Path Browser crash.
   (Patch by Roger Serwy)
 
diff --git a/Lib/idlelib/OutputWindow.py b/Lib/idlelib/OutputWindow.py
index 745ccd2..9dacc49 100644
--- a/Lib/idlelib/OutputWindow.py
+++ b/Lib/idlelib/OutputWindow.py
@@ -106,7 +106,7 @@ class OutputWindow(EditorWindow):
                     f = open(filename, "r")
                     f.close()
                     break
-                except IOError:
+                except OSError:
                     continue
         else:
             return None
diff --git a/Lib/idlelib/PathBrowser.py b/Lib/idlelib/PathBrowser.py
index 55bf1aa..ab05c67 100644
--- a/Lib/idlelib/PathBrowser.py
+++ b/Lib/idlelib/PathBrowser.py
@@ -45,7 +45,7 @@ class DirBrowserTreeItem(TreeItem):
     def GetSubList(self):
         try:
             names = os.listdir(self.dir or os.curdir)
-        except os.error:
+        except OSError:
             return []
         packages = []
         for name in names:
diff --git a/Lib/idlelib/PyShell.py b/Lib/idlelib/PyShell.py
index 38ed3af..9ccb31c 100644
--- a/Lib/idlelib/PyShell.py
+++ b/Lib/idlelib/PyShell.py
@@ -58,7 +58,7 @@ else:
         try:
             file.write(warnings.formatwarning(message, category, filename,
                                               lineno, line=line))
-        except IOError:
+        except OSError:
             pass  ## file (probably __stderr__) is invalid, warning dropped.
     warnings.showwarning = idle_showwarning
     def idle_formatwarning(message, category, filename, lineno, line=None):
@@ -211,7 +211,7 @@ class PyShellEditorWindow(EditorWindow):
         try:
             with open(self.breakpointPath, "r") as fp:
                 lines = fp.readlines()
-        except IOError:
+        except OSError:
             lines = []
         try:
             with open(self.breakpointPath, "w") as new_file:
@@ -222,7 +222,7 @@ class PyShellEditorWindow(EditorWindow):
                 breaks = self.breakpoints
                 if breaks:
                     new_file.write(filename + '=' + str(breaks) + '\n')
-        except IOError as err:
+        except OSError as err:
             if not getattr(self.root, "breakpoint_error_displayed", False):
                 self.root.breakpoint_error_displayed = True
                 tkMessageBox.showerror(title='IDLE Error',
@@ -393,7 +393,7 @@ class ModifiedInterpreter(InteractiveInterpreter):
             try:
                 self.rpcclt = MyRPCClient(addr)
                 break
-            except socket.error as err:
+            except OSError as err:
                 pass
         else:
             self.display_port_binding_error()
@@ -526,7 +526,7 @@ class ModifiedInterpreter(InteractiveInterpreter):
             return
         try:
             response = clt.pollresponse(self.active_seq, wait=0.05)
-        except (EOFError, IOError, KeyboardInterrupt):
+        except (EOFError, OSError, KeyboardInterrupt):
             # lost connection or subprocess terminated itself, restart
             # [the KBI is from rpc.SocketIO.handle_EOF()]
             if self.tkconsole.closing:
@@ -1012,7 +1012,10 @@ class PyShell(OutputWindow):
                 self.close()
                 return False
         else:
-            nosub = "==== No Subprocess ===="
+            nosub = ("==== No Subprocess ====\n\n" +
+                    "WARNING: Running IDLE without a Subprocess is deprecated\n" +
+                    "and will be removed in a later version. See Help/IDLE Help\n" +
+                    "for details.\n\n")
             sys.displayhook = rpc.displayhook
 
         self.write("Python %s on %s\n%s\n%s" %
@@ -1358,7 +1361,8 @@ USAGE: idle  [-deins] [-t title] [file]*
        idle  [-dns] [-t title] - [arg]*
 
   -h         print this help message and exit
-  -n         run IDLE without a subprocess (see Help/IDLE Help for details)
+  -n         run IDLE without a subprocess (DEPRECATED,
+             see Help/IDLE Help for details)
 
 The following options will override the IDLE 'settings' configuration:
 
@@ -1436,6 +1440,8 @@ def main():
         if o == '-i':
             enable_shell = True
         if o == '-n':
+            print(" Warning: running IDLE without a subprocess is deprecated.",
+                  file=sys.stderr)
             use_subprocess = False
         if o == '-r':
             script = a
diff --git a/Lib/idlelib/TreeWidget.py b/Lib/idlelib/TreeWidget.py
index d4e524b..833896c 100644
--- a/Lib/idlelib/TreeWidget.py
+++ b/Lib/idlelib/TreeWidget.py
@@ -382,7 +382,7 @@ class FileTreeItem(TreeItem):
         try:
             os.rename(self.path, newpath)
             self.path = newpath
-        except os.error:
+        except OSError:
             pass
 
     def GetIconName(self):
@@ -395,7 +395,7 @@ class FileTreeItem(TreeItem):
     def GetSubList(self):
         try:
             names = os.listdir(self.path)
-        except os.error:
+        except OSError:
             return []
         names.sort(key = os.path.normcase)
         sublist = []
diff --git a/Lib/idlelib/configHandler.py b/Lib/idlelib/configHandler.py
index 405c7a1..a193eb9 100644
--- a/Lib/idlelib/configHandler.py
+++ b/Lib/idlelib/configHandler.py
@@ -142,7 +142,7 @@ class IdleUserConfParser(IdleConfParser):
             fname = self.file
             try:
                 cfgFile = open(fname, 'w')
-            except IOError:
+            except OSError:
                 os.unlink(fname)
                 cfgFile = open(fname, 'w')
             with cfgFile:
@@ -207,7 +207,7 @@ class IdleConf:
                         userDir+',\n but the path does not exist.\n')
                 try:
                     sys.stderr.write(warn)
-                except IOError:
+                except OSError:
                     pass
                 userDir = '~'
         if userDir == "~": # still no path to home!
@@ -217,7 +217,7 @@ class IdleConf:
         if not os.path.exists(userDir):
             try:
                 os.mkdir(userDir)
-            except (OSError, IOError):
+            except OSError:
                 warn = ('\n Warning: unable to create user config directory\n'+
                         userDir+'\n Check path and permissions.\n Exiting!\n\n')
                 sys.stderr.write(warn)
@@ -251,7 +251,7 @@ class IdleConf:
                                                      raw=raw)))
             try:
                 sys.stderr.write(warning)
-            except IOError:
+            except OSError:
                 pass
         try:
             if self.defaultCfg[configType].has_option(section,option):
@@ -268,7 +268,7 @@ class IdleConf:
                        (option, section, default))
             try:
                 sys.stderr.write(warning)
-            except IOError:
+            except OSError:
                 pass
         return default
 
@@ -380,7 +380,7 @@ class IdleConf:
                            (element, themeName, theme[element]))
                 try:
                     sys.stderr.write(warning)
-                except IOError:
+                except OSError:
                     pass
             colour=cfgParser.Get(themeName,element,default=theme[element])
             theme[element]=colour
@@ -637,7 +637,7 @@ class IdleConf:
                                (event, keySetName, keyBindings[event]))
                     try:
                         sys.stderr.write(warning)
-                    except IOError:
+                    except OSError:
                         pass
         return keyBindings
 
diff --git a/Lib/idlelib/help.txt b/Lib/idlelib/help.txt
index 815ee40..c4e1231 100644
--- a/Lib/idlelib/help.txt
+++ b/Lib/idlelib/help.txt
@@ -1,142 +1,185 @@
 [See the end of this file for ** TIPS ** on using IDLE !!]
 
-Click on the dotted line at the top of a menu to "tear it off": a
-separate window containing the menu is created.
-
-File Menu:
-
-	New Window       -- Create a new editing window
-	Open...          -- Open an existing file
-	Recent Files...  -- Open a list of recent files
-	Open Module...   -- Open an existing module (searches sys.path)
-	Class Browser    -- Show classes and methods in current file
-	Path Browser     -- Show sys.path directories, modules, classes
+IDLE is the Python IDE built with the tkinter GUI toolkit.
+
+IDLE has the following features:
+-coded in 100% pure Python, using the tkinter GUI toolkit
+-cross-platform: works on Windows, Unix, and OS X
+-multi-window text editor with multiple undo, Python colorizing, smart indent,
+call tips, and many other features
+-Python shell window (a.k.a interactive interpreter)
+-debugger (not complete, but you can set breakpoints, view and step)
+
+Menus:
+
+IDLE has two window types the Shell window and the Editor window. It is
+possible to have multiple editor windows simultaneously. IDLE's
+menus dynamically change based on which window is currently selected. Each menu
+documented below indicates which window type it is associated with. Click on
+the dotted line at the top of a menu to "tear it off": a separate window
+containing the menu is created (for Unix and Windows only).
+
+File Menu (Shell and Editor):
+
+        New Window       -- Create a new editing window
+        Open...          -- Open an existing file
+        Open Module...   -- Open an existing module (searches sys.path)
+        Recent Files...  -- Open a list of recent files
+        Class Browser    -- Show classes and methods in current file
+        Path Browser     -- Show sys.path directories, modules, classes,
                             and methods
-	---
-	Save             -- Save current window to the associated file (unsaved
-		            windows have a * before and after the window title)
-
-	Save As...       -- Save current window to new file, which becomes
-		            the associated file
-	Save Copy As...  -- Save current window to different file
-		            without changing the associated file
-	---
-	Print Window     -- Print the current window
-	---
-	Close            -- Close current window (asks to save if unsaved)
-	Exit             -- Close all windows, quit (asks to save if unsaved)
-
-Edit Menu:
-
-	Undo             -- Undo last change to current window
-                            (A maximum of 1000 changes may be undone)
-	Redo             -- Redo last undone change to current window
-	---
-	Cut              -- Copy a selection into system-wide clipboard,
+        ---
+        Save             -- Save current window to the associated file (unsaved
+                            windows have a * before and after the window title)
+
+        Save As...       -- Save current window to new file, which becomes
+                            the associated file
+        Save Copy As...  -- Save current window to different file
+                            without changing the associated file
+        ---
+        Print Window     -- Print the current window
+        ---
+        Close            -- Close current window (asks to save if unsaved)
+        Exit             -- Close all windows, quit (asks to save if unsaved)
+
+Edit Menu (Shell and Editor):
+
+        Undo             -- Undo last change to current window
+                            (a maximum of 1000 changes may be undone)
+        Redo             -- Redo last undone change to current window
+        ---
+        Cut              -- Copy a selection into system-wide clipboard,
                             then delete the selection
-	Copy             -- Copy selection into system-wide clipboard
-	Paste            -- Insert system-wide clipboard into window
-	Select All       -- Select the entire contents of the edit buffer
-	---
-	Find...          -- Open a search dialog box with many options
-	Find Again       -- Repeat last search
-	Find Selection   -- Search for the string in the selection
-	Find in Files... -- Open a search dialog box for searching files
-	Replace...       -- Open a search-and-replace dialog box
-	Go to Line       -- Ask for a line number and show that line
-	Show Calltip     -- Open a small window with function param hints
-	Show Completions -- Open a scroll window allowing selection keywords
-			    and attributes. (see '*TIPS*', below)
-	Show Parens	 -- Highlight the surrounding parenthesis
-	Expand Word      -- Expand the word you have typed to match another
-		            word in the same buffer; repeat to get a
+        Copy             -- Copy selection into system-wide clipboard
+        Paste            -- Insert system-wide clipboard into window
+        Select All       -- Select the entire contents of the edit buffer
+        ---
+        Find...          -- Open a search dialog box with many options
+        Find Again       -- Repeat last search
+        Find Selection   -- Search for the string in the selection
+        Find in Files... -- Open a search dialog box for searching files
+        Replace...       -- Open a search-and-replace dialog box
+        Go to Line       -- Ask for a line number and show that line
+        Expand Word      -- Expand the word you have typed to match another
+                            word in the same buffer; repeat to get a
                             different expansion
-
-Format Menu (only in Edit window):
-
-	Indent Region       -- Shift selected lines right 4 spaces
-	Dedent Region       -- Shift selected lines left 4 spaces
-	Comment Out Region  -- Insert ## in front of selected lines
-	Uncomment Region    -- Remove leading # or ## from selected lines
-	Tabify Region       -- Turns *leading* stretches of spaces into tabs
-		(Note: We recommend using 4 space blocks to indent Python code.)
-	Untabify Region     -- Turn *all* tabs into the right number of spaces
-	New Indent Width... -- Open dialog to change indent width
-	Format Paragraph    -- Reformat the current blank-line-separated
-                               paragraph
-
-Run Menu (only in Edit window):
-
-	Python Shell -- Open or wake up the Python shell window
-	---
-	Check Module -- Run a syntax check on the module
-	Run Module   -- Execute the current file in the __main__ namespace
-
-Shell Menu (only in Shell window):
-
-	View Last Restart -- Scroll the shell window to the last restart
-	Restart Shell     -- Restart the interpreter with a fresh environment
-
-Debug Menu (only in Shell window):
-
-	Go to File/Line   -- look around the insert point for a filename
-		             and line number, open the file, and show the line
-	Debugger (toggle) -- Run commands in the shell under the debugger
-	Stack Viewer      -- Show the stack traceback of the last exception
-	Auto-open Stack Viewer (toggle) -- Open stack viewer on traceback
-
-Options Menu:
-
-	Configure IDLE -- Open a configuration dialog.  Fonts, indentation,
+        Show Calltip     -- After an unclosed parenthesis for a function, open
+                            a small window with function parameter hints
+        Show Parens      -- Highlight the surrounding parenthesis
+        Show Completions -- Open a scroll window allowing selection keywords
+                            and attributes. (see '*TIPS*', below)
+
+Format Menu (Editor window only):
+
+        Indent Region       -- Shift selected lines right by the indent width
+                               (default 4 spaces)
+        Dedent Region       -- Shift selected lines left by the indent width
+                               (default 4 spaces)
+        Comment Out Region  -- Insert ## in front of selected lines
+        Uncomment Region    -- Remove leading # or ## from selected lines
+        Tabify Region       -- Turns *leading* stretches of spaces into tabs.
+                (Note: We recommend using 4 space blocks to indent Python code.)
+        Untabify Region     -- Turn *all* tabs into the corrent number of spaces
+        Toggle tabs         -- Open a dialog to switch between indenting with
+                               spaces and tabs.
+        New Indent Width... -- Open a dialog to change indent width.  The
+                               accepted default by the Python community is 4
+                               spaces.
+        Format Paragraph    -- Reformat the current blank-line-separated
+                               paragraph. All lines in the paragraph will be
+                               formatted to less than 80 columns.
+        ---
+        Strip trailing whitespace -- Removed any space characters after the end
+                                     of the last non-space character
+
+Run Menu (Editor window only):
+
+        Python Shell -- Open or wake up the Python shell window
+        ---
+        Check Module -- Check the syntax of the module currently open in the
+                        Editor window.  If the module has not been saved IDLE
+                        will prompt the user to save the code.
+        Run Module   -- Restart the shell to clean the environment, then
+                        execute the currently open module. If the module has
+                        not been saved IDLE will prompt the user to save the
+                        code.
+
+Shell Menu (Shell window only):
+
+        View Last Restart -- Scroll the shell window to the last Shell restart
+        Restart Shell     -- Restart the shell to clean the environment
+
+Debug Menu (Shell window only):
+
+        Go to File/Line   -- Look around the insert point for a filename
+                             and line number, open the file, and show the line.
+                             Useful to view the source lines referenced in an
+                             exception traceback.  Available in the context
+                             menu of the Shell window.
+        Debugger (toggle) -- This feature is not complete and considered
+                             experimental. Run commands in the shell under the
+                             debugger.
+        Stack Viewer      -- Show the stack traceback of the last exception
+        Auto-open Stack Viewer (toggle) -- Toggle automatically opening the
+                                           stack viewer on unhandled
+                                           exception
+
+Options Menu (Shell and Editor):
+
+        Configure IDLE -- Open a configuration dialog.  Fonts, indentation,
                           keybindings, and color themes may be altered.
-                          Startup Preferences may be set, and Additional Help
-                          Sources can be specified.
-			  
-			  On OS X this menu is not present, use
-			  menu 'IDLE -> Preferences...' instead.
-	---
-	Code Context --	  Open a pane at the top of the edit window which
-			  shows the block context of the section of code
-			  which is scrolling off the top or the window.
-			  (Not present in Shell window.)
-
-Windows Menu:
-
-	Zoom Height -- toggles the window between configured size
-	and maximum height.
-	---
-	The rest of this menu lists the names of all open windows;
-	select one to bring it to the foreground (deiconifying it if
-	necessary).
+                          Startup Preferences may be set, and additional Help
+                          sources can be specified.
+
+        ---
+        Code Context (toggle) -- Open a pane at the top of the edit window
+                                 which shows the block context of the section
+                                 of code which is scrolling off the top or the
+                                 window. This is not present in the Shell
+                                 window only the Editor window.
+
+Windows Menu (Shell and Editor):
+
+        Zoom Height -- Toggles the window between normal size (40x80 initial
+        setting) and maximum height.  The initial size is in the Configure
+        IDLE dialog under the general tab.
+        ---
+        The rest of this menu lists the names of all open windows;
+        select one to bring it to the foreground (deiconifying it if
+        necessary).
 
 Help Menu:
 
-	About IDLE  -- Version, copyright, license, credits
-	IDLE Readme -- Background discussion and change details
-	---
-	IDLE Help   -- Display this file
-	Python Docs -- Access local Python documentation, if
-		       installed.  Otherwise, access www.python.org.
-	---
-	(Additional Help Sources may be added here)
-
-Edit context menu (Right-click / Control-click on OS X in Edit window):
-
-	Cut              -- Copy a selection into system-wide clipboard,
+        About IDLE  -- Version, copyright, license, credits
+        ---
+        IDLE Help   -- Display this file which is a help file for IDLE
+                       detailing the menu options, basic editing and navigation,
+                       and other tips.
+        Python Docs -- Access local Python documentation, if
+                       installed.  Or will start a web browser and open
+                       docs.python.org showing the latest Python documentation.
+        ---
+        Additional help sources may be added here with the Configure IDLE
+        dialog under the General tab.
+
+Editor context menu (Right-click / Control-click on OS X in Edit window):
+
+        Cut              -- Copy a selection into system-wide clipboard,
                             then delete the selection
-	Copy             -- Copy selection into system-wide clipboard
-	Paste            -- Insert system-wide clipboard into window
-	Set Breakpoint   -- Sets a breakpoint (when debugger open)
-	Clear Breakpoint -- Clears the breakpoint on that line
+        Copy             -- Copy selection into system-wide clipboard
+        Paste            -- Insert system-wide clipboard into window
+        Set Breakpoint   -- Sets a breakpoint. Breakpoints are only enabled
+                            when the debugger is open.
+        Clear Breakpoint -- Clears the breakpoint on that line
 
 Shell context menu (Right-click / Control-click on OS X in Shell window):
 
-	Cut              -- Copy a selection into system-wide clipboard,
+        Cut              -- Copy a selection into system-wide clipboard,
                             then delete the selection
-	Copy             -- Copy selection into system-wide clipboard
-	Paste            -- Insert system-wide clipboard into window
-	---
-	Go to file/line  -- Same as in Debug menu
+        Copy             -- Copy selection into system-wide clipboard
+        Paste            -- Insert system-wide clipboard into window
+        ---
+        Go to file/line  -- Same as in Debug menu
 
 
 ** TIPS **
@@ -144,160 +187,183 @@ Shell context menu (Right-click / Control-click on OS X in Shell window):
 
 Additional Help Sources:
 
-	Windows users can Google on zopeshelf.chm to access Zope help files in
-	the Windows help format.  The Additional Help Sources feature of the
-	configuration GUI supports .chm, along with any other filetypes
-	supported by your browser.  Supply a Menu Item title, and enter the
-	location in the Help File Path slot of the New Help Source dialog.  Use
-	http:// and/or www. to identify external URLs, or download the file and
-	browse for its path on your machine using the Browse button.
+        Windows users can Google on zopeshelf.chm to access Zope help files in
+        the Windows help format.  The Additional Help Sources feature of the
+        configuration GUI supports .chm, along with any other filetypes
+        supported by your browser.  Supply a Menu Item title, and enter the
+        location in the Help File Path slot of the New Help Source dialog.  Use
+        http:// and/or www. to identify external URLs, or download the file and
+        browse for its path on your machine using the Browse button.
 
-	All users can access the extensive sources of help, including
-	tutorials, available at www.python.org/doc.  Selected URLs can be added
-	or removed from the Help menu at any time using Configure IDLE.
+        All users can access the extensive sources of help, including
+        tutorials, available at docs.python.org.  Selected URLs can be added
+        or removed from the Help menu at any time using Configure IDLE.
 
 Basic editing and navigation:
 
-	Backspace deletes char to the left; DEL deletes char to the right.
-	Control-backspace deletes word left, Control-DEL deletes word right.
-	Arrow keys and Page Up/Down move around.
-	Control-left/right Arrow moves by words in a strange but useful way.
-	Home/End go to begin/end of line.
-	Control-Home/End go to begin/end of file.
-	Some useful Emacs bindings are inherited from Tcl/Tk:
-		Control-a     beginning of line
-		Control-e     end of line
-		Control-k     kill line (but doesn't put it in clipboard)
-		Control-l     center window around the insertion point
-	Standard Windows bindings may work on that platform.
-	Keybindings are selected in the Settings Dialog, look there.
+        Backspace deletes char to the left; DEL deletes char to the right.
+        Control-backspace deletes word left, Control-DEL deletes word right.
+        Arrow keys and Page Up/Down move around.
+        Control-left/right Arrow moves by words in a strange but useful way.
+        Home/End go to begin/end of line.
+        Control-Home/End go to begin/end of file.
+        Some useful Emacs bindings are inherited from Tcl/Tk:
+                Control-a     beginning of line
+                Control-e     end of line
+                Control-k     kill line (but doesn't put it in clipboard)
+                Control-l     center window around the insertion point
+        Standard keybindings (like Control-c to copy and Control-v to
+        paste) may work.  Keybindings are selected in the Configure IDLE
+        dialog.
 
 Automatic indentation:
 
-	After a block-opening statement, the next line is indented by 4 spaces
-	(in the Python Shell window by one tab).  After certain keywords
-	(break, return etc.) the next line is dedented.  In leading
-	indentation, Backspace deletes up to 4 spaces if they are there.  Tab
-	inserts spaces (in the Python Shell window one tab), number depends on
-	Indent Width.  (N.B. Currently tabs are restricted to four spaces due
-	to Tcl/Tk issues.)
+        After a block-opening statement, the next line is indented by 4 spaces
+        (in the Python Shell window by one tab).  After certain keywords
+        (break, return etc.) the next line is dedented.  In leading
+        indentation, Backspace deletes up to 4 spaces if they are there.  Tab
+        inserts spaces (in the Python Shell window one tab), number depends on
+        Indent Width. Currently tabs are restricted to four spaces due
+        to Tcl/Tk limitations.
 
         See also the indent/dedent region commands in the edit menu.
 
 Completions:
 
-	Completions are supplied for functions, classes, and attributes of
-	classes, both built-in and user-defined.  Completions are also provided
-	for filenames.
-
-	The AutoCompleteWindow (ACW) will open after a predefined delay
-	(default is two seconds) after a '.' or (in a string) an os.sep is
-	typed.  If after one of those characters (plus zero or more other
-	characters) you type a Tab the ACW will open immediately if a possible
-	continuation is found.
-
-	If there is only one possible completion for the characters entered, a
-	Tab will supply that completion without opening the ACW.
-
-	'Show Completions' will force open a completions window.  In an empty
-	string, this will contain the files in the current directory.  On a
-	blank line, it will contain the built-in and user-defined functions and
-	classes in the current name spaces, plus any modules imported.  If some
-	characters have been entered, the ACW will attempt to be more specific.
-
-	If string of characters is typed, the ACW selection will jump to the
-	entry most closely matching those characters. Entering a Tab will cause
-	the longest non-ambiguous match to be entered in the Edit window or
-	Shell.  Two Tabs in a row will supply the current ACW selection, as
-	will Return or a double click.  Cursor keys, Page Up/Down, mouse
-	selection, and the scrollwheel all operate on the ACW.
-
-	'Hidden' attributes can be accessed by typing the beginning of hidden
-	name after a '.'.  e.g. '_'.  This allows access to modules with
-	'__all__' set, or to class-private attributes.
-
-	Completions and the 'Expand Word' facility can save a lot of typing!
-
-	Completions are currently limited to those in the namespaces.  Names in
-	an Edit window which are not via __main__ or sys.modules will not be
-	found.  Run the module once with your imports to correct this
-	situation.  Note that IDLE itself places quite a few modules in
-	sys.modules, so much can be found by default, e.g. the re module.
-
-	If you don't like the ACW popping up unbidden, simply make the delay
-	longer or disable the extension.  OTOH, you could make the delay zero.
-
-	You could also switch off the CallTips extension.  (We will be adding
-	a delay to the call tip window.)
+        Completions are supplied for functions, classes, and attributes of
+        classes, both built-in and user-defined.  Completions are also provided
+        for filenames.
+
+        The AutoCompleteWindow (ACW) will open after a predefined delay
+        (default is two seconds) after a '.' or (in a string) an os.sep is
+        typed.  If after one of those characters (plus zero or more other
+        characters) a tab is typed the ACW will open immediately if a possible
+        continuation is found.
+
+        If there is only one possible completion for the characters entered, a
+        tab will supply that completion without opening the ACW.
+
+        'Show Completions' will force open a completions window, by default the
+        Control-space keys will open a completions window.  In an empty
+        string, this will contain the files in the current directory.  On a
+        blank line, it will contain the built-in and user-defined functions and
+        classes in the current name spaces, plus any modules imported.  If some
+        characters have been entered, the ACW will attempt to be more specific.
+
+        If string of characters is typed, the ACW selection will jump to the
+        entry most closely matching those characters. Entering a tab will cause
+        the longest non-ambiguous match to be entered in the Edit window or
+        Shell.  Two tabs in a row will supply the current ACW selection, as
+        will return or a double click.  Cursor keys, Page Up/Down, mouse
+        selection, and the scroll wheel all operate on the ACW.
+
+        "Hidden" attributes can be accessed by typing the beginning of hidden
+        name after a '.',  e.g. '_'.  This allows access to modules with
+        '__all__' set, or to class-private attributes.
+
+        Completions and the 'Expand Word' facility can save a lot of typing!
+
+        Completions are currently limited to those in the namespaces.  Names in
+        an Editor window which are not via __main__ or sys.modules will not be
+        found.  Run the module once with your imports to correct this
+        situation.  Note that IDLE itself places quite a few modules in
+        sys.modules, so much can be found by default, e.g. the re module.
+
+        If you don't like the ACW popping up unbidden, simply make the delay
+        longer or disable the extension.  Or another option is the delay could
+        be set to zero. Another alternative to preventing ACW popups is to
+        disable the call tips extension.
 
 Python Shell window:
 
-	Control-c interrupts executing command.
-	Control-d sends end-of-file; closes window if typed at >>> prompt
-		(this is Control-z on Windows).
+        Control-c interrupts executing command.
+        Control-d sends end-of-file; closes window if typed at >>> prompt
+                (this is Control-z on Windows).
+        Alt-/ expand word is also useful to reduce typing.
 
     Command history:
 
-	Alt-p retrieves previous command matching what you have typed.
-	Alt-n retrieves next.
-	      (These are Control-p, Control-n on OS X)
-	Return while cursor is on a previous command retrieves that command.
-	Expand word is also useful to reduce typing.
+        Alt-p retrieves previous command matching what you have typed. On OS X
+        use Control-p.
+        Alt-n retrieves next. On OS X use Control-n.
+        Return while cursor is on a previous command retrieves that command.
 
     Syntax colors:
 
-	The coloring is applied in a background "thread", so you may
-	occasionally see uncolorized text.  To change the color
-	scheme, use the Configure IDLE / Highlighting dialog.
+        The coloring is applied in a background "thread", so you may
+        occasionally see uncolorized text.  To change the color
+        scheme, use the Configure IDLE / Highlighting dialog.
 
     Python default syntax colors:
 
-	Keywords	orange
-	Builtins	royal purple
-	Strings		green
-	Comments	red
-	Definitions	blue
+        Keywords        orange
+        Builtins        royal purple
+        Strings         green
+        Comments        red
+        Definitions     blue
 
     Shell default colors:
 
-	Console output	brown
-	stdout		blue
-	stderr		red
-	stdin		black
+        Console output  brown
+        stdout          blue
+        stderr          red
+        stdin           black
 
 Other preferences:
 
-	The font preferences, keybinding, and startup preferences can
-	be changed using the Settings dialog.
+        The font preferences, highlighting, keys, and general preferences can
+        be changed via the Configure IDLE menu option.  Be sure to note that
+        keys can be user defined, IDLE ships with four built in key sets. In
+        addition a user can create a custom key set in the Configure IDLE
+        dialog under the keys tab.
 
 Command line usage:
 
-	Enter idle -h at the command prompt to get a usage message.
-
-Running without a subprocess:
-
-	If IDLE is started with the -n command line switch it will run in a
-	single process and will not create the subprocess which runs the RPC
-	Python execution server.  This can be useful if Python cannot create
-	the subprocess or the RPC socket interface on your platform.  However,
-	in this mode user code is not isolated from IDLE itself.  Also, the
-	environment is not restarted when Run/Run Module (F5) is selected.  If
-	your code has been modified, you must reload() the affected modules and
-	re-import any specific items (e.g. from foo import baz) if the changes
-	are to take effect.  For these reasons, it is preferable to run IDLE
-	with the default subprocess if at all possible.
+        Enter idle -h at the command prompt to get a usage message.
+
+        idle.py [-c command] [-d] [-e] [-s] [-t title] [arg] ...
+
+        -c command  run this command
+        -d          enable debugger
+        -e          edit mode; arguments are files to be edited
+        -s          run $IDLESTARTUP or $PYTHONSTARTUP first
+        -t title    set title of shell window
+
+        If there are arguments:
+        1. If -e is used, arguments are files opened for editing and sys.argv
+           reflects the arguments passed to IDLE itself.
+        2. Otherwise, if -c is used, all arguments are placed in
+           sys.argv[1:...], with sys.argv[0] set to -c.
+        3. Otherwise, if neither -e nor -c is used, the first argument is a
+           script which is executed with the remaining arguments in
+           sys.argv[1:...]  and sys.argv[0] set to the script name.  If the
+           script name is -, no script is executed but an interactive Python
+           session is started; the arguments are still available in sys.argv.
+
+Running without a subprocess: (DEPRECATED in Python 3.5 see Issue 16123)
+
+        If IDLE is started with the -n command line switch it will run in a
+        single process and will not create the subprocess which runs the RPC
+        Python execution server.  This can be useful if Python cannot create
+        the subprocess or the RPC socket interface on your platform.  However,
+        in this mode user code is not isolated from IDLE itself.  Also, the
+        environment is not restarted when Run/Run Module (F5) is selected.  If
+        your code has been modified, you must reload() the affected modules and
+        re-import any specific items (e.g. from foo import baz) if the changes
+        are to take effect.  For these reasons, it is preferable to run IDLE
+        with the default subprocess if at all possible.
 
 Extensions:
 
-	IDLE contains an extension facility.  See the beginning of
-	config-extensions.def in the idlelib directory for further information.
-	The default extensions are currently:
-
-		FormatParagraph
-		AutoExpand
-		ZoomHeight
-		ScriptBinding
-		CallTips
-		ParenMatch
-		AutoComplete
-		CodeContext
+        IDLE contains an extension facility.  See the beginning of
+        config-extensions.def in the idlelib directory for further information.
+        The default extensions are currently:
+
+                FormatParagraph
+                AutoExpand
+                ZoomHeight
+                ScriptBinding
+                CallTips
+                ParenMatch
+                AutoComplete
+                CodeContext
diff --git a/Lib/idlelib/idlever.py b/Lib/idlelib/idlever.py
index 8d8317d..efe96a4 100644
--- a/Lib/idlelib/idlever.py
+++ b/Lib/idlelib/idlever.py
@@ -1 +1 @@
-IDLE_VERSION = "3.3.0"
+IDLE_VERSION = "3.4.0a0"
diff --git a/Lib/idlelib/rpc.py b/Lib/idlelib/rpc.py
index 77cb3ac..2bf4fdf 100644
--- a/Lib/idlelib/rpc.py
+++ b/Lib/idlelib/rpc.py
@@ -199,7 +199,7 @@ class SocketIO(object):
             raise
         except KeyboardInterrupt:
             raise
-        except socket.error:
+        except OSError:
             raise
         except Exception as ex:
             return ("CALLEXC", ex)
@@ -339,8 +339,8 @@ class SocketIO(object):
                 r, w, x = select.select([], [self.sock], [])
                 n = self.sock.send(s[:BUFSIZE])
             except (AttributeError, TypeError):
-                raise IOError("socket no longer exists")
-            except socket.error:
+                raise OSError("socket no longer exists")
+            except OSError:
                 raise
             else:
                 s = s[n:]
@@ -357,7 +357,7 @@ class SocketIO(object):
                 return None
             try:
                 s = self.sock.recv(BUFSIZE)
-            except socket.error:
+            except OSError:
                 raise EOFError
             if len(s) == 0:
                 raise EOFError
@@ -537,7 +537,7 @@ class RPCClient(SocketIO):
             SocketIO.__init__(self, working_sock)
         else:
             print("** Invalid host: ", address, file=sys.__stderr__)
-            raise socket.error
+            raise OSError
 
     def get_remote_proxy(self, oid):
         return RPCProxy(self, oid)
diff --git a/Lib/idlelib/run.py b/Lib/idlelib/run.py
index d105912..c66679c 100644
--- a/Lib/idlelib/run.py
+++ b/Lib/idlelib/run.py
@@ -137,8 +137,8 @@ def manage_socket(address):
         try:
             server = MyRPCServer(address, MyHandler)
             break
-        except socket.error as err:
-            print("IDLE Subprocess: socket error: " + err.args[1] +
+        except OSError as err:
+            print("IDLE Subprocess: OSError: " + err.args[1] +
                   ", retrying....", file=sys.__stderr__)
             socket_error = err
     else:
diff --git a/Lib/idlelib/textView.py b/Lib/idlelib/textView.py
index 1eaa464..ae1f195 100644
--- a/Lib/idlelib/textView.py
+++ b/Lib/idlelib/textView.py
@@ -66,7 +66,7 @@ def view_file(parent, title, filename, encoding=None, modal=True):
     try:
         with open(filename, 'r', encoding=encoding) as file:
             contents = file.read()
-    except IOError:
+    except OSError:
         import tkinter.messagebox as tkMessageBox
         tkMessageBox.showerror(title='File Load Error',
                                message='Unable to load file %r .' % filename,
diff --git a/Lib/imaplib.py b/Lib/imaplib.py
index 3f8c65a..fba3bca 100644
--- a/Lib/imaplib.py
+++ b/Lib/imaplib.py
@@ -174,7 +174,7 @@ class IMAP4:
         except Exception:
             try:
                 self.shutdown()
-            except socket.error:
+            except OSError:
                 pass
             raise
 
@@ -267,7 +267,7 @@ class IMAP4:
         self.file.close()
         try:
             self.sock.shutdown(socket.SHUT_RDWR)
-        except socket.error as e:
+        except OSError as e:
             # The server might already have closed the connection
             if e.errno != errno.ENOTCONN:
                 raise
@@ -899,7 +899,7 @@ class IMAP4:
 
         try:
             self.send(data + CRLF)
-        except (socket.error, OSError) as val:
+        except OSError as val:
             raise self.abort('socket error: %s' % val)
 
         if literal is None:
@@ -924,7 +924,7 @@ class IMAP4:
             try:
                 self.send(literal)
                 self.send(CRLF)
-            except (socket.error, OSError) as val:
+            except OSError as val:
                 raise self.abort('socket error: %s' % val)
 
             if not literator:
diff --git a/Lib/imghdr.py b/Lib/imghdr.py
index 6ee45da..0cba063 100644
--- a/Lib/imghdr.py
+++ b/Lib/imghdr.py
@@ -149,7 +149,7 @@ def testall(list, recursive, toplevel):
             sys.stdout.flush()
             try:
                 print(what(filename))
-            except IOError:
+            except OSError:
                 print('*** not found ***')
 
 if __name__ == '__main__':
diff --git a/Lib/importlib/_bootstrap.py b/Lib/importlib/_bootstrap.py
index 15fe156..6b2221d 100644
--- a/Lib/importlib/_bootstrap.py
+++ b/Lib/importlib/_bootstrap.py
@@ -237,7 +237,7 @@ class _ModuleLock:
                     self.wakeup.release()
 
     def __repr__(self):
-        return "_ModuleLock(%r) at %d" % (self.name, id(self))
+        return "_ModuleLock({!r}) at {}".format(self.name, id(self))
 
 
 class _DummyModuleLock:
@@ -258,7 +258,7 @@ class _DummyModuleLock:
         self.count -= 1
 
     def __repr__(self):
-        return "_DummyModuleLock(%r) at %d" % (self.name, id(self))
+        return "_DummyModuleLock({!r}) at {}".format(self.name, id(self))
 
 
 # The following two functions are for consumption by Python/import.c.
@@ -623,6 +623,80 @@ def _find_module_shim(self, fullname):
     return loader
 
 
+def _validate_bytecode_header(data, source_stats=None, name=None, path=None):
+    """Validate the header of the passed-in bytecode against source_stats (if
+    given) and returning the bytecode that can be compiled by compile().
+
+    All other arguments are used to enhance error reporting.
+
+    ImportError is raised when the magic number is incorrect or the bytecode is
+    found to be stale. EOFError is raised when the data is found to be
+    truncated.
+
+    """
+    exc_details = {}
+    if name is not None:
+        exc_details['name'] = name
+    else:
+        # To prevent having to make all messages have a conditional name.
+        name = '<bytecode>'
+    if path is not None:
+        exc_details['path'] = path
+    magic = data[:4]
+    raw_timestamp = data[4:8]
+    raw_size = data[8:12]
+    if magic != _MAGIC_BYTES:
+        msg = 'bad magic number in {!r}: {!r}'.format(name, magic)
+        raise ImportError(msg, **exc_details)
+    elif len(raw_timestamp) != 4:
+        message = 'incomplete timestamp in {!r}'.format(name)
+        _verbose_message(message)
+        raise EOFError(message)
+    elif len(raw_size) != 4:
+        message = 'incomplete size in {!r}'.format(name)
+        _verbose_message(message)
+        raise EOFError(message)
+    if source_stats is not None:
+        try:
+            source_mtime = int(source_stats['mtime'])
+        except KeyError:
+            pass
+        else:
+            if _r_long(raw_timestamp) != source_mtime:
+                message = 'bytecode is stale for {!r}'.format(name)
+                _verbose_message(message)
+                raise ImportError(message, **exc_details)
+        try:
+            source_size = source_stats['size'] & 0xFFFFFFFF
+        except KeyError:
+            pass
+        else:
+            if _r_long(raw_size) != source_size:
+                raise ImportError("bytecode is stale for {!r}".format(name),
+                                  **exc_details)
+    return data[12:]
+
+
+def _compile_bytecode(data, name=None, bytecode_path=None, source_path=None):
+    """Compile bytecode as returned by _validate_bytecode_header()."""
+    code = marshal.loads(data)
+    if isinstance(code, _code_type):
+        _verbose_message('code object from {!r}', bytecode_path)
+        if source_path is not None:
+            _imp._fix_co_filename(code, source_path)
+        return code
+    else:
+        raise ImportError("Non-code object in {!r}".format(bytecode_path),
+                          name=name, path=bytecode_path)
+
+def _code_to_bytecode(code, mtime=0, source_size=0):
+    """Compile a code object into bytecode for writing out to a byte-compiled
+    file."""
+    data = bytearray(_MAGIC_BYTES)
+    data.extend(_w_long(mtime))
+    data.extend(_w_long(source_size))
+    data.extend(marshal.dumps(code))
+    return data
 
 
 # Loaders #####################################################################
@@ -755,7 +829,7 @@ class WindowsRegistryFinder:
     def _open_registry(cls, key):
         try:
             return _winreg.OpenKey(_winreg.HKEY_CURRENT_USER, key)
-        except WindowsError:
+        except OSError:
             return _winreg.OpenKey(_winreg.HKEY_LOCAL_MACHINE, key)
 
     @classmethod
@@ -769,7 +843,7 @@ class WindowsRegistryFinder:
         try:
             with cls._open_registry(key) as hkey:
                 filepath = _winreg.QueryValue(hkey, "")
-        except WindowsError:
+        except OSError:
             return None
         return filepath
 
@@ -801,51 +875,6 @@ class _LoaderBasics:
         tail_name = fullname.rpartition('.')[2]
         return filename_base == '__init__' and tail_name != '__init__'
 
-    def _bytes_from_bytecode(self, fullname, data, bytecode_path, source_stats):
-        """Return the marshalled bytes from bytecode, verifying the magic
-        number, timestamp and source size along the way.
-
-        If source_stats is None then skip the timestamp check.
-
-        """
-        magic = data[:4]
-        raw_timestamp = data[4:8]
-        raw_size = data[8:12]
-        if magic != _MAGIC_BYTES:
-            msg = 'bad magic number in {!r}: {!r}'.format(fullname, magic)
-            raise ImportError(msg, name=fullname, path=bytecode_path)
-        elif len(raw_timestamp) != 4:
-            message = 'bad timestamp in {}'.format(fullname)
-            _verbose_message(message)
-            raise EOFError(message)
-        elif len(raw_size) != 4:
-            message = 'bad size in {}'.format(fullname)
-            _verbose_message(message)
-            raise EOFError(message)
-        if source_stats is not None:
-            try:
-                source_mtime = int(source_stats['mtime'])
-            except KeyError:
-                pass
-            else:
-                if _r_long(raw_timestamp) != source_mtime:
-                    message = 'bytecode is stale for {}'.format(fullname)
-                    _verbose_message(message)
-                    raise ImportError(message, name=fullname,
-                                      path=bytecode_path)
-            try:
-                source_size = source_stats['size'] & 0xFFFFFFFF
-            except KeyError:
-                pass
-            else:
-                if _r_long(raw_size) != source_size:
-                    raise ImportError(
-                        "bytecode is stale for {}".format(fullname),
-                        name=fullname, path=bytecode_path)
-        # Can't return the code object as errors from marshal loading need to
-        # propagate even when source is available.
-        return data[12:]
-
     @module_for_loader
     def _load_module(self, module, *, sourceless=False):
         """Helper for load_module able to handle either source or sourceless
@@ -915,7 +944,7 @@ class SourceLoader(_LoaderBasics):
         path = self.get_filename(fullname)
         try:
             source_bytes = self.get_data(path)
-        except IOError as exc:
+        except OSError as exc:
             raise ImportError("source not available through get_data()",
                               name=fullname) from exc
         readsource = _io.BytesIO(source_bytes).readline
@@ -931,6 +960,14 @@ class SourceLoader(_LoaderBasics):
             raise ImportError("Failed to decode source file",
                               name=fullname) from exc
 
+    def source_to_code(self, data, path, *, _optimize=-1):
+        """Return the code object compiled from source.
+
+        The 'data' argument can be any object type that compile() supports.
+        """
+        return _call_with_frames_removed(compile, data, path, 'exec',
+                                        dont_inherit=True, optimize=_optimize)
+
     def get_code(self, fullname):
         """Concrete implementation of InspectLoader.get_code.
 
@@ -953,39 +990,28 @@ class SourceLoader(_LoaderBasics):
                 source_mtime = int(st['mtime'])
                 try:
                     data = self.get_data(bytecode_path)
-                except IOError:
+                except OSError:
                     pass
                 else:
                     try:
-                        bytes_data = self._bytes_from_bytecode(fullname, data,
-                                                               bytecode_path,
-                                                               st)
+                        bytes_data = _validate_bytecode_header(data,
+                                source_stats=st, name=fullname,
+                                path=bytecode_path)
                     except (ImportError, EOFError):
                         pass
                     else:
                         _verbose_message('{} matches {}', bytecode_path,
                                         source_path)
-                        found = marshal.loads(bytes_data)
-                        if isinstance(found, _code_type):
-                            _imp._fix_co_filename(found, source_path)
-                            _verbose_message('code object from {}',
-                                            bytecode_path)
-                            return found
-                        else:
-                            msg = "Non-code object in {}"
-                            raise ImportError(msg.format(bytecode_path),
-                                              name=fullname, path=bytecode_path)
+                        return _compile_bytecode(bytes_data, name=fullname,
+                                                 bytecode_path=bytecode_path,
+                                                 source_path=source_path)
         source_bytes = self.get_data(source_path)
-        code_object = _call_with_frames_removed(compile,
-                          source_bytes, source_path, 'exec',
-                          dont_inherit=True)
+        code_object = self.source_to_code(source_bytes, source_path)
         _verbose_message('code object from {}', source_path)
         if (not sys.dont_write_bytecode and bytecode_path is not None and
-            source_mtime is not None):
-            data = bytearray(_MAGIC_BYTES)
-            data.extend(_w_long(source_mtime))
-            data.extend(_w_long(len(source_bytes)))
-            data.extend(marshal.dumps(code_object))
+                source_mtime is not None):
+            data = _code_to_bytecode(code_object, source_mtime,
+                    len(source_bytes))
             try:
                 self._cache_bytecode(source_path, bytecode_path, data)
                 _verbose_message('wrote {!r}', bytecode_path)
@@ -1092,14 +1118,8 @@ class SourcelessFileLoader(FileLoader, _LoaderBasics):
     def get_code(self, fullname):
         path = self.get_filename(fullname)
         data = self.get_data(path)
-        bytes_data = self._bytes_from_bytecode(fullname, data, path, None)
-        found = marshal.loads(bytes_data)
-        if isinstance(found, _code_type):
-            _verbose_message('code object from {!r}', path)
-            return found
-        else:
-            raise ImportError("Non-code object in {}".format(path),
-                              name=fullname, path=path)
+        bytes_data = _validate_bytecode_header(data, name=fullname, path=path)
+        return _compile_bytecode(bytes_data, name=fullname, bytecode_path=path)
 
     def get_source(self, fullname):
         """Return None as there is no source code."""
@@ -1440,7 +1460,7 @@ class FileFinder:
         return path_hook_for_FileFinder
 
     def __repr__(self):
-        return "FileFinder(%r)" % (self.path,)
+        return "FileFinder({!r})".format(self.path)
 
 
 # Import itself ###############################################################
@@ -1720,7 +1740,7 @@ def _setup(sys_module, _imp_module):
             builtin_module = sys.modules[builtin_name]
         setattr(self_module, builtin_name, builtin_module)
 
-    os_details = ('posix', ['/']), ('nt', ['\\', '/']), ('os2', ['\\', '/'])
+    os_details = ('posix', ['/']), ('nt', ['\\', '/'])
     for builtin_os, path_separators in os_details:
         # Assumption made in _path_join()
         assert all(len(sep) == 1 for sep in path_separators)
@@ -1731,9 +1751,6 @@ def _setup(sys_module, _imp_module):
         else:
             try:
                 os_module = BuiltinImporter.load_module(builtin_os)
-                # TODO: rip out os2 code after 3.3 is released as per PEP 11
-                if builtin_os == 'os2' and 'EMX GCC' in sys.version:
-                    path_sep = path_separators[1]
                 break
             except ImportError:
                 continue
diff --git a/Lib/importlib/abc.py b/Lib/importlib/abc.py
index 387567a..11e45f4 100644
--- a/Lib/importlib/abc.py
+++ b/Lib/importlib/abc.py
@@ -225,180 +225,3 @@ class SourceLoader(_bootstrap.SourceLoader, ResourceLoader, ExecutionLoader):
         raise NotImplementedError
 
 _register(SourceLoader, machinery.SourceFileLoader)
-
-class PyLoader(SourceLoader):
-
-    """Implement the deprecated PyLoader ABC in terms of SourceLoader.
-
-    This class has been deprecated! It is slated for removal in Python 3.4.
-    If compatibility with Python 3.1 is not needed then implement the
-    SourceLoader ABC instead of this class. If Python 3.1 compatibility is
-    needed, then use the following idiom to have a single class that is
-    compatible with Python 3.1 onwards::
-
-        try:
-            from importlib.abc import SourceLoader
-        except ImportError:
-            from importlib.abc import PyLoader as SourceLoader
-
-
-        class CustomLoader(SourceLoader):
-            def get_filename(self, fullname):
-                # Implement ...
-
-            def source_path(self, fullname):
-                '''Implement source_path in terms of get_filename.'''
-                try:
-                    return self.get_filename(fullname)
-                except ImportError:
-                    return None
-
-            def is_package(self, fullname):
-                filename = os.path.basename(self.get_filename(fullname))
-                return os.path.splitext(filename)[0] == '__init__'
-
-    """
-
-    @abc.abstractmethod
-    def is_package(self, fullname):
-        raise NotImplementedError
-
-    @abc.abstractmethod
-    def source_path(self, fullname):
-        """Abstract method.  Accepts a str module name and returns the path to
-        the source code for the module."""
-        raise NotImplementedError
-
-    def get_filename(self, fullname):
-        """Implement get_filename in terms of source_path.
-
-        As get_filename should only return a source file path there is no
-        chance of the path not existing but loading still being possible, so
-        ImportError should propagate instead of being turned into returning
-        None.
-
-        """
-        warnings.warn("importlib.abc.PyLoader is deprecated and is "
-                            "slated for removal in Python 3.4; "
-                            "use SourceLoader instead. "
-                            "See the importlib documentation on how to be "
-                            "compatible with Python 3.1 onwards.",
-                        DeprecationWarning)
-        path = self.source_path(fullname)
-        if path is None:
-            raise ImportError(name=fullname)
-        else:
-            return path
-
-
-class PyPycLoader(PyLoader):
-
-    """Abstract base class to assist in loading source and bytecode by
-    requiring only back-end storage methods to be implemented.
-
-    This class has been deprecated! Removal is slated for Python 3.4. Implement
-    the SourceLoader ABC instead. If Python 3.1 compatibility is needed, see
-    PyLoader.
-
-    The methods get_code, get_source, and load_module are implemented for the
-    user.
-
-    """
-
-    def get_filename(self, fullname):
-        """Return the source or bytecode file path."""
-        path = self.source_path(fullname)
-        if path is not None:
-            return path
-        path = self.bytecode_path(fullname)
-        if path is not None:
-            return path
-        raise ImportError("no source or bytecode path available for "
-                            "{0!r}".format(fullname), name=fullname)
-
-    def get_code(self, fullname):
-        """Get a code object from source or bytecode."""
-        warnings.warn("importlib.abc.PyPycLoader is deprecated and slated for "
-                            "removal in Python 3.4; use SourceLoader instead. "
-                            "If Python 3.1 compatibility is required, see the "
-                            "latest documentation for PyLoader.",
-                        DeprecationWarning)
-        source_timestamp = self.source_mtime(fullname)
-        # Try to use bytecode if it is available.
-        bytecode_path = self.bytecode_path(fullname)
-        if bytecode_path:
-            data = self.get_data(bytecode_path)
-            try:
-                magic = data[:4]
-                if len(magic) < 4:
-                    raise ImportError(
-                        "bad magic number in {}".format(fullname),
-                        name=fullname, path=bytecode_path)
-                raw_timestamp = data[4:8]
-                if len(raw_timestamp) < 4:
-                    raise EOFError("bad timestamp in {}".format(fullname))
-                pyc_timestamp = _bootstrap._r_long(raw_timestamp)
-                raw_source_size = data[8:12]
-                if len(raw_source_size) != 4:
-                    raise EOFError("bad file size in {}".format(fullname))
-                # Source size is unused as the ABC does not provide a way to
-                # get the size of the source ahead of reading it.
-                bytecode = data[12:]
-                # Verify that the magic number is valid.
-                if imp.get_magic() != magic:
-                    raise ImportError(
-                        "bad magic number in {}".format(fullname),
-                        name=fullname, path=bytecode_path)
-                # Verify that the bytecode is not stale (only matters when
-                # there is source to fall back on.
-                if source_timestamp:
-                    if pyc_timestamp < source_timestamp:
-                        raise ImportError("bytecode is stale", name=fullname,
-                                          path=bytecode_path)
-            except (ImportError, EOFError):
-                # If source is available give it a shot.
-                if source_timestamp is not None:
-                    pass
-                else:
-                    raise
-            else:
-                # Bytecode seems fine, so try to use it.
-                return marshal.loads(bytecode)
-        elif source_timestamp is None:
-            raise ImportError("no source or bytecode available to create code "
-                              "object for {0!r}".format(fullname),
-                              name=fullname)
-        # Use the source.
-        source_path = self.source_path(fullname)
-        if source_path is None:
-            message = "a source path must exist to load {0}".format(fullname)
-            raise ImportError(message, name=fullname)
-        source = self.get_data(source_path)
-        code_object = compile(source, source_path, 'exec', dont_inherit=True)
-        # Generate bytecode and write it out.
-        if not sys.dont_write_bytecode:
-            data = bytearray(imp.get_magic())
-            data.extend(_bootstrap._w_long(source_timestamp))
-            data.extend(_bootstrap._w_long(len(source) & 0xFFFFFFFF))
-            data.extend(marshal.dumps(code_object))
-            self.write_bytecode(fullname, data)
-        return code_object
-
-    @abc.abstractmethod
-    def source_mtime(self, fullname):
-        """Abstract method. Accepts a str filename and returns an int
-        modification time for the source of the module."""
-        raise NotImplementedError
-
-    @abc.abstractmethod
-    def bytecode_path(self, fullname):
-        """Abstract method. Accepts a str filename and returns the str pathname
-        to the bytecode for the module."""
-        raise NotImplementedError
-
-    @abc.abstractmethod
-    def write_bytecode(self, fullname, bytecode):
-        """Abstract method.  Accepts a str filename and bytes object
-        representing the bytecode for the module.  Returns a boolean
-        representing whether the bytecode was written or not."""
-        raise NotImplementedError
diff --git a/Lib/inspect.py b/Lib/inspect.py
index 7a7bb91..3661316 100644
--- a/Lib/inspect.py
+++ b/Lib/inspect.py
@@ -545,13 +545,13 @@ def findsource(object):
 
     The argument may be a module, class, method, function, traceback, frame,
     or code object.  The source code is returned as a list of all the lines
-    in the file and the line number indexes a line in that list.  An IOError
+    in the file and the line number indexes a line in that list.  An OSError
     is raised if the source code cannot be retrieved."""
 
     file = getfile(object)
     sourcefile = getsourcefile(object)
     if not sourcefile and file[0] + file[-1] != '<>':
-        raise IOError('source code not available')
+        raise OSError('source code not available')
     file = sourcefile if sourcefile else file
 
     module = getmodule(object, file)
@@ -560,7 +560,7 @@ def findsource(object):
     else:
         lines = linecache.getlines(file)
     if not lines:
-        raise IOError('could not get source code')
+        raise OSError('could not get source code')
 
     if ismodule(object):
         return lines, 0
@@ -586,7 +586,7 @@ def findsource(object):
             candidates.sort()
             return lines, candidates[0][1]
         else:
-            raise IOError('could not find class definition')
+            raise OSError('could not find class definition')
 
     if ismethod(object):
         object = object.__func__
@@ -598,14 +598,14 @@ def findsource(object):
         object = object.f_code
     if iscode(object):
         if not hasattr(object, 'co_firstlineno'):
-            raise IOError('could not find function definition')
+            raise OSError('could not find function definition')
         lnum = object.co_firstlineno - 1
         pat = re.compile(r'^(\s*def\s)|(.*(?<!\w)lambda(:|\s))|^(\s*@)')
         while lnum > 0:
             if pat.match(lines[lnum]): break
             lnum = lnum - 1
         return lines, lnum
-    raise IOError('could not find code object')
+    raise OSError('could not find code object')
 
 def getcomments(object):
     """Get lines of comments immediately preceding an object's source code.
@@ -614,7 +614,7 @@ def getcomments(object):
     """
     try:
         lines, lnum = findsource(object)
-    except (IOError, TypeError):
+    except (OSError, TypeError):
         return None
 
     if ismodule(object):
@@ -710,7 +710,7 @@ def getsourcelines(object):
     The argument may be a module, class, method, function, traceback, frame,
     or code object.  The source code is returned as a list of the lines
     corresponding to the object and the line number indicates where in the
-    original source file the first line of code was found.  An IOError is
+    original source file the first line of code was found.  An OSError is
     raised if the source code cannot be retrieved."""
     lines, lnum = findsource(object)
 
@@ -722,7 +722,7 @@ def getsource(object):
 
     The argument may be a module, class, method, function, traceback, frame,
     or code object.  The source code is returned as a single string.  An
-    IOError is raised if the source code cannot be retrieved."""
+    OSError is raised if the source code cannot be retrieved."""
     lines, lnum = getsourcelines(object)
     return ''.join(lines)
 
@@ -1122,7 +1122,7 @@ def getframeinfo(frame, context=1):
         start = lineno - 1 - context//2
         try:
             lines, lnum = findsource(frame)
-        except IOError:
+        except OSError:
             lines = index = None
         else:
             start = max(start, 1)
diff --git a/Lib/io.py b/Lib/io.py
index bda4def..39878b8 100644
--- a/Lib/io.py
+++ b/Lib/io.py
@@ -4,7 +4,7 @@ builtin open function is defined in this module.
 At the top of the I/O hierarchy is the abstract base class IOBase. It
 defines the basic interface to a stream. Note, however, that there is no
 separation between reading and writing to streams; implementations are
-allowed to raise an IOError if they do not support a given operation.
+allowed to raise an OSError if they do not support a given operation.
 
 Extending IOBase is RawIOBase which deals simply with the reading and
 writing of raw bytes to a stream. FileIO subclasses RawIOBase to provide
diff --git a/Lib/json/__init__.py b/Lib/json/__init__.py
index 44f49c4..3b23224 100644
--- a/Lib/json/__init__.py
+++ b/Lib/json/__init__.py
@@ -39,8 +39,7 @@ Compact encoding::
 Pretty printing::
 
     >>> import json
-    >>> print(json.dumps({'4': 5, '6': 7}, sort_keys=True,
-    ...                  indent=4, separators=(',', ': ')))
+    >>> print(json.dumps({'4': 5, '6': 7}, sort_keys=True, indent=4))
     {
         "4": 5,
         "6": 7
@@ -146,13 +145,12 @@ def dump(obj, fp, skipkeys=False, ensure_ascii=True, check_circular=True,
     If ``indent`` is a non-negative integer, then JSON array elements and
     object members will be pretty-printed with that indent level. An indent
     level of 0 will only insert newlines. ``None`` is the most compact
-    representation.  Since the default item separator is ``', '``,  the
-    output might include trailing whitespace when ``indent`` is specified.
-    You can use ``separators=(',', ': ')`` to avoid this.
+    representation.
 
-    If ``separators`` is an ``(item_separator, dict_separator)`` tuple
-    then it will be used instead of the default ``(', ', ': ')`` separators.
-    ``(',', ':')`` is the most compact JSON representation.
+    If specified, ``separators`` should be an ``(item_separator, key_separator)``
+    tuple.  The default is ``(', ', ': ')`` if *indent* is ``None`` and
+    ``(',', ': ')`` otherwise.  To get the most compact JSON representation,
+    you should specify ``(',', ':')`` to eliminate whitespace.
 
     ``default(obj)`` is a function that should return a serializable version
     of obj or raise TypeError. The default simply raises TypeError.
@@ -209,13 +207,12 @@ def dumps(obj, skipkeys=False, ensure_ascii=True, check_circular=True,
     If ``indent`` is a non-negative integer, then JSON array elements and
     object members will be pretty-printed with that indent level. An indent
     level of 0 will only insert newlines. ``None`` is the most compact
-    representation.  Since the default item separator is ``', '``,  the
-    output might include trailing whitespace when ``indent`` is specified.
-    You can use ``separators=(',', ': ')`` to avoid this.
+    representation.
 
-    If ``separators`` is an ``(item_separator, dict_separator)`` tuple
-    then it will be used instead of the default ``(', ', ': ')`` separators.
-    ``(',', ':')`` is the most compact JSON representation.
+    If specified, ``separators`` should be an ``(item_separator, key_separator)``
+    tuple.  The default is ``(', ', ': ')`` if *indent* is ``None`` and
+    ``(',', ': ')`` otherwise.  To get the most compact JSON representation,
+    you should specify ``(',', ':')`` to eliminate whitespace.
 
     ``default(obj)`` is a function that should return a serializable version
     of obj or raise TypeError. The default simply raises TypeError.
diff --git a/Lib/json/decoder.py b/Lib/json/decoder.py
index 07fd696..7e5a099 100644
--- a/Lib/json/decoder.py
+++ b/Lib/json/decoder.py
@@ -1,9 +1,6 @@
 """Implementation of JSONDecoder
 """
-import binascii
 import re
-import sys
-import struct
 
 from json import scanner
 try:
@@ -15,14 +12,9 @@ __all__ = ['JSONDecoder']
 
 FLAGS = re.VERBOSE | re.MULTILINE | re.DOTALL
 
-def _floatconstants():
-    _BYTES = binascii.unhexlify(b'7FF80000000000007FF0000000000000')
-    if sys.byteorder != 'big':
-        _BYTES = _BYTES[:8][::-1] + _BYTES[8:][::-1]
-    nan, inf = struct.unpack('dd', _BYTES)
-    return nan, inf, -inf
-
-NaN, PosInf, NegInf = _floatconstants()
+NaN = float('nan')
+PosInf = float('inf')
+NegInf = float('-inf')
 
 
 def linecol(doc, pos):
@@ -196,8 +188,8 @@ def JSONObject(s_and_end, strict, scan_once, object_hook, object_pairs_hook,
 
         try:
             value, end = scan_once(s, end)
-        except StopIteration:
-            raise ValueError(errmsg("Expecting object", s, end))
+        except StopIteration as err:
+            raise ValueError(errmsg("Expecting value", s, err.value)) from None
         pairs_append((key, value))
         try:
             nextchar = s[end]
@@ -240,8 +232,8 @@ def JSONArray(s_and_end, scan_once, _w=WHITESPACE.match, _ws=WHITESPACE_STR):
     while True:
         try:
             value, end = scan_once(s, end)
-        except StopIteration:
-            raise ValueError(errmsg("Expecting object", s, end))
+        except StopIteration as err:
+            raise ValueError(errmsg("Expecting value", s, err.value)) from None
         _append(value)
         nextchar = s[end:end + 1]
         if nextchar in _ws:
@@ -251,7 +243,7 @@ def JSONArray(s_and_end, scan_once, _w=WHITESPACE.match, _ws=WHITESPACE_STR):
         if nextchar == ']':
             break
         elif nextchar != ',':
-            raise ValueError(errmsg("Expecting ',' delimiter", s, end))
+            raise ValueError(errmsg("Expecting ',' delimiter", s, end - 1))
         try:
             if s[end] in _ws:
                 end += 1
@@ -366,6 +358,6 @@ class JSONDecoder(object):
         """
         try:
             obj, end = self.scan_once(s, idx)
-        except StopIteration:
-            raise ValueError("No JSON object could be decoded")
+        except StopIteration as err:
+            raise ValueError(errmsg("Expecting value", s, err.value)) from None
         return obj, end
diff --git a/Lib/json/encoder.py b/Lib/json/encoder.py
index e1ed21f..93b5ea7 100644
--- a/Lib/json/encoder.py
+++ b/Lib/json/encoder.py
@@ -125,14 +125,12 @@ class JSONEncoder(object):
         If indent is a non-negative integer, then JSON array
         elements and object members will be pretty-printed with that
         indent level.  An indent level of 0 will only insert newlines.
-        None is the most compact representation.  Since the default
-        item separator is ', ',  the output might include trailing
-        whitespace when indent is specified.  You can use
-        separators=(',', ': ') to avoid this.
+        None is the most compact representation.
 
-        If specified, separators should be a (item_separator, key_separator)
-        tuple.  The default is (', ', ': ').  To get the most compact JSON
-        representation you should specify (',', ':') to eliminate whitespace.
+        If specified, separators should be an (item_separator, key_separator)
+        tuple.  The default is (', ', ': ') if *indent* is ``None`` and
+        (',', ': ') otherwise.  To get the most compact JSON representation,
+        you should specify (',', ':') to eliminate whitespace.
 
         If specified, default is a function that gets called for objects
         that can't otherwise be serialized.  It should return a JSON encodable
@@ -148,6 +146,8 @@ class JSONEncoder(object):
         self.indent = indent
         if separators is not None:
             self.item_separator, self.key_separator = separators
+        elif indent is not None:
+            self.item_separator = ','
         if default is not None:
             self.default = default
 
@@ -308,8 +308,7 @@ def _make_iterencode(markers, _default, _encoder, _indent, _floatstr,
                     chunks = _iterencode_dict(value, _current_indent_level)
                 else:
                     chunks = _iterencode(value, _current_indent_level)
-                for chunk in chunks:
-                    yield chunk
+                yield from chunks
         if newline_indent is not None:
             _current_indent_level -= 1
             yield '\n' + _indent * _current_indent_level
@@ -384,8 +383,7 @@ def _make_iterencode(markers, _default, _encoder, _indent, _floatstr,
                     chunks = _iterencode_dict(value, _current_indent_level)
                 else:
                     chunks = _iterencode(value, _current_indent_level)
-                for chunk in chunks:
-                    yield chunk
+                yield from chunks
         if newline_indent is not None:
             _current_indent_level -= 1
             yield '\n' + _indent * _current_indent_level
@@ -407,11 +405,9 @@ def _make_iterencode(markers, _default, _encoder, _indent, _floatstr,
         elif isinstance(o, float):
             yield _floatstr(o)
         elif isinstance(o, (list, tuple)):
-            for chunk in _iterencode_list(o, _current_indent_level):
-                yield chunk
+            yield from _iterencode_list(o, _current_indent_level)
         elif isinstance(o, dict):
-            for chunk in _iterencode_dict(o, _current_indent_level):
-                yield chunk
+            yield from _iterencode_dict(o, _current_indent_level)
         else:
             if markers is not None:
                 markerid = id(o)
@@ -419,8 +415,7 @@ def _make_iterencode(markers, _default, _encoder, _indent, _floatstr,
                     raise ValueError("Circular reference detected")
                 markers[markerid] = o
             o = _default(o)
-            for chunk in _iterencode(o, _current_indent_level):
-                yield chunk
+            yield from _iterencode(o, _current_indent_level)
             if markers is not None:
                 del markers[markerid]
     return _iterencode
diff --git a/Lib/json/scanner.py b/Lib/json/scanner.py
index 23eef61..86426cd 100644
--- a/Lib/json/scanner.py
+++ b/Lib/json/scanner.py
@@ -29,7 +29,7 @@ def py_make_scanner(context):
         try:
             nextchar = string[idx]
         except IndexError:
-            raise StopIteration
+            raise StopIteration(idx)
 
         if nextchar == '"':
             return parse_string(string, idx + 1, strict)
@@ -60,7 +60,7 @@ def py_make_scanner(context):
         elif nextchar == '-' and string[idx:idx + 9] == '-Infinity':
             return parse_constant('-Infinity'), idx + 9
         else:
-            raise StopIteration
+            raise StopIteration(idx)
 
     def scan_once(string, idx):
         try:
diff --git a/Lib/json/tool.py b/Lib/json/tool.py
index 0f108c6..9ab6d65 100644
--- a/Lib/json/tool.py
+++ b/Lib/json/tool.py
@@ -31,8 +31,7 @@ def main():
         except ValueError as e:
             raise SystemExit(e)
     with outfile:
-        json.dump(obj, outfile, sort_keys=True,
-                  indent=4, separators=(',', ': '))
+        json.dump(obj, outfile, sort_keys=True, indent=4)
         outfile.write('\n')
 
 
diff --git a/Lib/lib2to3/btm_utils.py b/Lib/lib2to3/btm_utils.py
index 2276dc9..339750e 100644
--- a/Lib/lib2to3/btm_utils.py
+++ b/Lib/lib2to3/btm_utils.py
@@ -96,8 +96,7 @@ class MinNode(object):
     def leaves(self):
         "Generator that returns the leaves of the tree"
         for child in self.children:
-            for x in child.leaves():
-                yield x
+            yield from child.leaves()
         if not self.children:
             yield self
 
@@ -277,7 +276,6 @@ def rec_test(sequence, test_func):
     sub-iterables"""
     for x in sequence:
         if isinstance(x, (list, tuple)):
-            for y in rec_test(x, test_func):
-                yield y
+            yield from rec_test(x, test_func)
         else:
             yield test_func(x)
diff --git a/Lib/lib2to3/fixer_util.py b/Lib/lib2to3/fixer_util.py
index 60d219f..6e259c5 100644
--- a/Lib/lib2to3/fixer_util.py
+++ b/Lib/lib2to3/fixer_util.py
@@ -129,6 +129,29 @@ def FromImport(package_name, name_leafs):
     imp = Node(syms.import_from, children)
     return imp
 
+def ImportAndCall(node, results, names):
+    """Returns an import statement and calls a method
+    of the module:
+
+    import module
+    module.name()"""
+    obj = results["obj"].clone()
+    if obj.type == syms.arglist:
+        newarglist = obj.clone()
+    else:
+        newarglist = Node(syms.arglist, [obj.clone()])
+    after = results["after"]
+    if after:
+        after = [n.clone() for n in after]
+    new = Node(syms.power,
+               Attr(Name(names[0]), Name(names[1])) +
+               [Node(syms.trailer,
+                     [results["lpar"].clone(),
+                      newarglist,
+                      results["rpar"].clone()])] + after)
+    new.prefix = node.prefix
+    return new
+
 
 ###########################################################
 ### Determine whether a node represents a given literal
diff --git a/Lib/lib2to3/fixes/fix_intern.py b/Lib/lib2to3/fixes/fix_intern.py
index 6be11cd..fb2973c 100644
--- a/Lib/lib2to3/fixes/fix_intern.py
+++ b/Lib/lib2to3/fixes/fix_intern.py
@@ -6,9 +6,8 @@
 intern(s) -> sys.intern(s)"""
 
 # Local imports
-from .. import pytree
 from .. import fixer_base
-from ..fixer_util import Name, Attr, touch_import
+from ..fixer_util import ImportAndCall, touch_import
 
 
 class FixIntern(fixer_base.BaseFix):
@@ -26,21 +25,7 @@ class FixIntern(fixer_base.BaseFix):
     """
 
     def transform(self, node, results):
-        syms = self.syms
-        obj = results["obj"].clone()
-        if obj.type == syms.arglist:
-            newarglist = obj.clone()
-        else:
-            newarglist = pytree.Node(syms.arglist, [obj.clone()])
-        after = results["after"]
-        if after:
-            after = [n.clone() for n in after]
-        new = pytree.Node(syms.power,
-                          Attr(Name("sys"), Name("intern")) +
-                          [pytree.Node(syms.trailer,
-                                       [results["lpar"].clone(),
-                                        newarglist,
-                                        results["rpar"].clone()])] + after)
-        new.prefix = node.prefix
+        names = ('sys', 'intern')
+        new = ImportAndCall(node, results, names)
         touch_import(None, 'sys', node)
         return new
diff --git a/Lib/lib2to3/fixes/fix_reload.py b/Lib/lib2to3/fixes/fix_reload.py
new file mode 100644
index 0000000..1855357
--- /dev/null
+++ b/Lib/lib2to3/fixes/fix_reload.py
@@ -0,0 +1,28 @@
+"""Fixer for reload().
+
+reload(s) -> imp.reload(s)"""
+
+# Local imports
+from .. import fixer_base
+from ..fixer_util import ImportAndCall, touch_import
+
+
+class FixReload(fixer_base.BaseFix):
+    BM_compatible = True
+    order = "pre"
+
+    PATTERN = """
+    power< 'reload'
+           trailer< lpar='('
+                    ( not(arglist | argument<any '=' any>) obj=any
+                      | obj=arglist<(not argument<any '=' any>) any ','> )
+                    rpar=')' >
+           after=any*
+    >
+    """
+
+    def transform(self, node, results):
+        names = ('imp', 'reload')
+        new = ImportAndCall(node, results, names)
+        touch_import(None, 'imp', node)
+        return new
diff --git a/Lib/lib2to3/main.py b/Lib/lib2to3/main.py
index f9cc18b..93bae90 100644
--- a/Lib/lib2to3/main.py
+++ b/Lib/lib2to3/main.py
@@ -90,11 +90,11 @@ class StdoutRefactoringTool(refactor.MultiprocessRefactoringTool):
             if os.path.lexists(backup):
                 try:
                     os.remove(backup)
-                except os.error as err:
+                except OSError as err:
                     self.log_message("Can't remove backup %s", backup)
             try:
                 os.rename(filename, backup)
-            except os.error as err:
+            except OSError as err:
                 self.log_message("Can't rename %s to %s", filename, backup)
         # Actually write the new file
         write = super(StdoutRefactoringTool, self).write_file
diff --git a/Lib/lib2to3/pgen2/conv.py b/Lib/lib2to3/pgen2/conv.py
index bf49762..ed0cac5 100644
--- a/Lib/lib2to3/pgen2/conv.py
+++ b/Lib/lib2to3/pgen2/conv.py
@@ -60,7 +60,7 @@ class Converter(grammar.Grammar):
         """
         try:
             f = open(filename)
-        except IOError as err:
+        except OSError as err:
             print("Can't open %s: %s" % (filename, err))
             return False
         self.symbol2number = {}
@@ -111,7 +111,7 @@ class Converter(grammar.Grammar):
         """
         try:
             f = open(filename)
-        except IOError as err:
+        except OSError as err:
             print("Can't open %s: %s" % (filename, err))
             return False
         # The code below essentially uses f's iterator-ness!
diff --git a/Lib/lib2to3/pgen2/driver.py b/Lib/lib2to3/pgen2/driver.py
index 4c611c6..3ccc69d 100644
--- a/Lib/lib2to3/pgen2/driver.py
+++ b/Lib/lib2to3/pgen2/driver.py
@@ -123,7 +123,7 @@ def load_grammar(gt="Grammar.txt", gp=None,
             logger.info("Writing grammar tables to %s", gp)
             try:
                 g.dump(gp)
-            except IOError as e:
+            except OSError as e:
                 logger.info("Writing failed:"+str(e))
     else:
         g = grammar.Grammar()
diff --git a/Lib/lib2to3/pytree.py b/Lib/lib2to3/pytree.py
index 17cbf0a..c4a1be3 100644
--- a/Lib/lib2to3/pytree.py
+++ b/Lib/lib2to3/pytree.py
@@ -194,8 +194,7 @@ class Base(object):
 
     def leaves(self):
         for child in self.children:
-            for x in child.leaves():
-                yield x
+            yield from child.leaves()
 
     def depth(self):
         if self.parent is None:
@@ -274,16 +273,14 @@ class Node(Base):
     def post_order(self):
         """Return a post-order iterator for the tree."""
         for child in self.children:
-            for node in child.post_order():
-                yield node
+            yield from child.post_order()
         yield self
 
     def pre_order(self):
         """Return a pre-order iterator for the tree."""
         yield self
         for child in self.children:
-            for node in child.pre_order():
-                yield node
+            yield from child.pre_order()
 
     def _prefix_getter(self):
         """
diff --git a/Lib/lib2to3/refactor.py b/Lib/lib2to3/refactor.py
index 201e193..8100317 100644
--- a/Lib/lib2to3/refactor.py
+++ b/Lib/lib2to3/refactor.py
@@ -326,7 +326,7 @@ class RefactoringTool(object):
         """
         try:
             f = open(filename, "rb")
-        except IOError as err:
+        except OSError as err:
             self.log_error("Can't open %s: %s", filename, err)
             return None, None
         try:
@@ -534,12 +534,12 @@ class RefactoringTool(object):
         """
         try:
             f = _open_with_encoding(filename, "w", encoding=encoding)
-        except os.error as err:
+        except OSError as err:
             self.log_error("Can't create %s: %s", filename, err)
             return
         try:
             f.write(_to_system_newlines(new_text))
-        except os.error as err:
+        except OSError as err:
             self.log_error("Can't write %s: %s", filename, err)
         finally:
             f.close()
diff --git a/Lib/lib2to3/tests/pytree_idempotency.py b/Lib/lib2to3/tests/pytree_idempotency.py
index a02bbfe..731c403 100755
--- a/Lib/lib2to3/tests/pytree_idempotency.py
+++ b/Lib/lib2to3/tests/pytree_idempotency.py
@@ -53,7 +53,7 @@ def main():
     for dir in sys.path:
         try:
             names = os.listdir(dir)
-        except os.error:
+        except OSError:
             continue
         print("Scanning", dir, "...", file=sys.stderr)
         for name in names:
diff --git a/Lib/lib2to3/tests/test_fixers.py b/Lib/lib2to3/tests/test_fixers.py
index 914b3bf..d7659fa 100644
--- a/Lib/lib2to3/tests/test_fixers.py
+++ b/Lib/lib2to3/tests/test_fixers.py
@@ -282,6 +282,65 @@ class Test_apply(FixerTestCase):
         b = """f(*args, **kwds)"""
         self.check(a, b)
 
+class Test_reload(FixerTestCase):
+    fixer = "reload"
+
+    def test(self):
+        b = """reload(a)"""
+        a = """import imp\nimp.reload(a)"""
+        self.check(b, a)
+
+    def test_comment(self):
+        b = """reload( a ) # comment"""
+        a = """import imp\nimp.reload( a ) # comment"""
+        self.check(b, a)
+
+        # PEP 8 comments
+        b = """reload( a )  # comment"""
+        a = """import imp\nimp.reload( a )  # comment"""
+        self.check(b, a)
+
+    def test_space(self):
+        b = """reload( a )"""
+        a = """import imp\nimp.reload( a )"""
+        self.check(b, a)
+
+        b = """reload( a)"""
+        a = """import imp\nimp.reload( a)"""
+        self.check(b, a)
+
+        b = """reload(a )"""
+        a = """import imp\nimp.reload(a )"""
+        self.check(b, a)
+
+    def test_unchanged(self):
+        s = """reload(a=1)"""
+        self.unchanged(s)
+
+        s = """reload(f, g)"""
+        self.unchanged(s)
+
+        s = """reload(f, *h)"""
+        self.unchanged(s)
+
+        s = """reload(f, *h, **i)"""
+        self.unchanged(s)
+
+        s = """reload(f, **i)"""
+        self.unchanged(s)
+
+        s = """reload(*h, **i)"""
+        self.unchanged(s)
+
+        s = """reload(*h)"""
+        self.unchanged(s)
+
+        s = """reload(**i)"""
+        self.unchanged(s)
+
+        s = """reload()"""
+        self.unchanged(s)
+
 class Test_intern(FixerTestCase):
     fixer = "intern"
 
diff --git a/Lib/linecache.py b/Lib/linecache.py
index c3f2c3f..02a9eb5 100644
--- a/Lib/linecache.py
+++ b/Lib/linecache.py
@@ -59,7 +59,7 @@ def checkcache(filename=None):
             continue   # no-op for files loaded via a __loader__
         try:
             stat = os.stat(fullname)
-        except os.error:
+        except OSError:
             del cache[filename]
             continue
         if size != stat.st_size or mtime != stat.st_mtime:
@@ -91,7 +91,7 @@ def updatecache(filename, module_globals=None):
             if name and get_source:
                 try:
                     data = get_source(name)
-                except (ImportError, IOError):
+                except (ImportError, OSError):
                     pass
                 else:
                     if data is None:
@@ -118,14 +118,14 @@ def updatecache(filename, module_globals=None):
             try:
                 stat = os.stat(fullname)
                 break
-            except os.error:
+            except OSError:
                 pass
         else:
             return []
     try:
         with tokenize.open(fullname) as fp:
             lines = fp.readlines()
-    except IOError:
+    except OSError:
         return []
     if lines and not lines[-1].endswith('\n'):
         lines[-1] += '\n'
diff --git a/Lib/logging/__init__.py b/Lib/logging/__init__.py
index fa03f78..244c915 100644
--- a/Lib/logging/__init__.py
+++ b/Lib/logging/__init__.py
@@ -67,7 +67,7 @@ else: #pragma: no cover
         """Return the frame object for the caller's stack frame."""
         try:
             raise Exception
-        except:
+        except Exception:
             return sys.exc_info()[2].tb_frame.f_back
 
 # _srcfile is only used in conjunction with sys._getframe().
@@ -880,16 +880,27 @@ class Handler(Filterer):
         The record which was being processed is passed in to this method.
         """
         if raiseExceptions and sys.stderr:  # see issue 13807
-            ei = sys.exc_info()
+            t, v, tb = sys.exc_info()
             try:
-                traceback.print_exception(ei[0], ei[1], ei[2],
-                                          None, sys.stderr)
-                sys.stderr.write('Logged from file %s, line %s\n' % (
-                                 record.filename, record.lineno))
-            except IOError: #pragma: no cover
+                sys.stderr.write('--- Logging error ---\n')
+                traceback.print_exception(t, v, tb, None, sys.stderr)
+                sys.stderr.write('Call stack:\n')
+                # Walk the stack frame up until we're out of logging,
+                # so as to print the calling context.
+                frame = tb.tb_frame
+                while (frame and os.path.dirname(frame.f_code.co_filename) ==
+                       __path__[0]):
+                    frame = frame.f_back
+                if frame:
+                    traceback.print_stack(frame, file=sys.stderr)
+                else:
+                    # couldn't find the right stack frame, for some reason
+                    sys.stderr.write('Logged from file %s, line %s\n' % (
+                                     record.filename, record.lineno))
+            except OSError: #pragma: no cover
                 pass    # see issue 5971
             finally:
-                del ei
+                del t, v, tb
 
 class StreamHandler(Handler):
     """
@@ -939,9 +950,7 @@ class StreamHandler(Handler):
             stream.write(msg)
             stream.write(self.terminator)
             self.flush()
-        except (KeyboardInterrupt, SystemExit): #pragma: no cover
-            raise
-        except:
+        except Exception:
             self.handleError(record)
 
 class FileHandler(StreamHandler):
@@ -1830,7 +1839,7 @@ def shutdown(handlerList=_handlerList):
                     h.acquire()
                     h.flush()
                     h.close()
-                except (IOError, ValueError):
+                except (OSError, ValueError):
                     # Ignore errors which might be caused
                     # because handlers have been closed but
                     # references to them are still around at
@@ -1838,7 +1847,7 @@ def shutdown(handlerList=_handlerList):
                     pass
                 finally:
                     h.release()
-        except:
+        except: # ignore everything, as we're shutting down
             if raiseExceptions:
                 raise
             #else, swallow
diff --git a/Lib/logging/config.py b/Lib/logging/config.py
index 5ef5c91..5eae183 100644
--- a/Lib/logging/config.py
+++ b/Lib/logging/config.py
@@ -1,4 +1,4 @@
-# Copyright 2001-2010 by Vinay Sajip. All Rights Reserved.
+# Copyright 2001-2012 by Vinay Sajip. All Rights Reserved.
 #
 # Permission to use, copy, modify, and distribute this software and its
 # documentation for any purpose and without fee is hereby granted,
@@ -19,7 +19,7 @@ Configuration functions for the logging package for Python. The core package
 is based on PEP 282 and comments thereto in comp.lang.python, and influenced
 by Apache's log4j system.
 
-Copyright (C) 2001-2010 Vinay Sajip. All Rights Reserved.
+Copyright (C) 2001-2012 Vinay Sajip. All Rights Reserved.
 
 To use, simply 'import logging' and log away!
 """
@@ -61,11 +61,14 @@ def fileConfig(fname, defaults=None, disable_existing_loggers=True):
     """
     import configparser
 
-    cp = configparser.ConfigParser(defaults)
-    if hasattr(fname, 'readline'):
-        cp.read_file(fname)
+    if isinstance(fname, configparser.RawConfigParser):
+        cp = fname
     else:
-        cp.read(fname)
+        cp = configparser.ConfigParser(defaults)
+        if hasattr(fname, 'readline'):
+            cp.read_file(fname)
+        else:
+            cp.read(fname)
 
     formatters = _create_formatters(cp)
 
@@ -707,6 +710,7 @@ class DictConfigurator(BaseConfigurator):
                 'address' in config:
                 config['address'] = self.as_tuple(config['address'])
             factory = klass
+        props = config.pop('.', None)
         kwargs = dict([(k, config[k]) for k in config if valid_ident(k)])
         try:
             result = factory(**kwargs)
@@ -725,6 +729,9 @@ class DictConfigurator(BaseConfigurator):
             result.setLevel(logging._checkLevel(level))
         if filters:
             self.add_filters(result, filters)
+        if props:
+            for name, value in props.items():
+                setattr(result, name, value)
         return result
 
     def add_handlers(self, logger, handlers):
@@ -773,7 +780,7 @@ def dictConfig(config):
     dictConfigClass(config).configure()
 
 
-def listen(port=DEFAULT_LOGGING_CONFIG_PORT):
+def listen(port=DEFAULT_LOGGING_CONFIG_PORT, verify=None):
     """
     Start up a socket server on the specified port, and listen for new
     configurations.
@@ -782,6 +789,15 @@ def listen(port=DEFAULT_LOGGING_CONFIG_PORT):
     Returns a Thread object on which you can call start() to start the server,
     and which you can join() when appropriate. To stop the server, call
     stopListening().
+
+    Use the ``verify`` argument to verify any bytes received across the wire
+    from a client. If specified, it should be a callable which receives a
+    single argument - the bytes of configuration data received across the
+    network - and it should return either ``None``, to indicate that the
+    passed in bytes could not be verified and should be discarded, or a
+    byte string which is then passed to the configuration machinery as
+    normal. Note that you can return transformed bytes, e.g. by decrypting
+    the bytes passed in.
     """
     if not thread: #pragma: no cover
         raise NotImplementedError("listen() needs threading to work")
@@ -809,25 +825,26 @@ def listen(port=DEFAULT_LOGGING_CONFIG_PORT):
                     chunk = self.connection.recv(slen)
                     while len(chunk) < slen:
                         chunk = chunk + conn.recv(slen - len(chunk))
-                    chunk = chunk.decode("utf-8")
-                    try:
-                        import json
-                        d =json.loads(chunk)
-                        assert isinstance(d, dict)
-                        dictConfig(d)
-                    except:
-                        #Apply new configuration.
-
-                        file = io.StringIO(chunk)
+                    if self.server.verify is not None:
+                        chunk = self.server.verify(chunk)
+                    if chunk is not None:   # verified, can process
+                        chunk = chunk.decode("utf-8")
                         try:
-                            fileConfig(file)
-                        except (KeyboardInterrupt, SystemExit): #pragma: no cover
-                            raise
-                        except:
-                            traceback.print_exc()
+                            import json
+                            d =json.loads(chunk)
+                            assert isinstance(d, dict)
+                            dictConfig(d)
+                        except Exception:
+                            #Apply new configuration.
+
+                            file = io.StringIO(chunk)
+                            try:
+                                fileConfig(file)
+                            except Exception:
+                                traceback.print_exc()
                     if self.server.ready:
                         self.server.ready.set()
-            except socket.error as e:
+            except OSError as e:
                 if not isinstance(e.args, tuple):
                     raise
                 else:
@@ -843,13 +860,14 @@ def listen(port=DEFAULT_LOGGING_CONFIG_PORT):
         allow_reuse_address = 1
 
         def __init__(self, host='localhost', port=DEFAULT_LOGGING_CONFIG_PORT,
-                     handler=None, ready=None):
+                     handler=None, ready=None, verify=None):
             ThreadingTCPServer.__init__(self, (host, port), handler)
             logging._acquireLock()
             self.abort = 0
             logging._releaseLock()
             self.timeout = 1
             self.ready = ready
+            self.verify = verify
 
         def serve_until_stopped(self):
             import select
@@ -867,16 +885,18 @@ def listen(port=DEFAULT_LOGGING_CONFIG_PORT):
 
     class Server(threading.Thread):
 
-        def __init__(self, rcvr, hdlr, port):
+        def __init__(self, rcvr, hdlr, port, verify):
             super(Server, self).__init__()
             self.rcvr = rcvr
             self.hdlr = hdlr
             self.port = port
+            self.verify = verify
             self.ready = threading.Event()
 
         def run(self):
             server = self.rcvr(port=self.port, handler=self.hdlr,
-                               ready=self.ready)
+                               ready=self.ready,
+                               verify=self.verify)
             if self.port == 0:
                 self.port = server.server_address[1]
             self.ready.set()
@@ -886,7 +906,7 @@ def listen(port=DEFAULT_LOGGING_CONFIG_PORT):
             logging._releaseLock()
             server.serve_until_stopped()
 
-    return Server(ConfigSocketReceiver, ConfigStreamHandler, port)
+    return Server(ConfigSocketReceiver, ConfigStreamHandler, port, verify)
 
 def stopListening():
     """
diff --git a/Lib/logging/handlers.py b/Lib/logging/handlers.py
index f286cd6..1491b47 100644
--- a/Lib/logging/handlers.py
+++ b/Lib/logging/handlers.py
@@ -72,9 +72,7 @@ class BaseRotatingHandler(logging.FileHandler):
             if self.shouldRollover(record):
                 self.doRollover()
             logging.FileHandler.emit(self, record)
-        except (KeyboardInterrupt, SystemExit): #pragma: no cover
-            raise
-        except:
+        except Exception:
             self.handleError(record)
 
     def rotation_filename(self, default_name):
@@ -496,15 +494,7 @@ class SocketHandler(logging.Handler):
         A factory method which allows subclasses to define the precise
         type of socket they want.
         """
-        s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
-        if hasattr(s, 'settimeout'):
-            s.settimeout(timeout)
-        try:
-            s.connect((self.host, self.port))
-            return s
-        except socket.error:
-            s.close()
-            raise
+        return socket.create_connection((self.host, self.port), timeout=timeout)
 
     def createSocket(self):
         """
@@ -524,7 +514,7 @@ class SocketHandler(logging.Handler):
             try:
                 self.sock = self.makeSocket()
                 self.retryTime = None # next time, no delay before trying
-            except socket.error:
+            except OSError:
                 #Creation failed, so set the retry time and return.
                 if self.retryTime is None:
                     self.retryPeriod = self.retryStart
@@ -548,16 +538,8 @@ class SocketHandler(logging.Handler):
         #but are still unable to connect.
         if self.sock:
             try:
-                if hasattr(self.sock, "sendall"):
-                    self.sock.sendall(s)
-                else: #pragma: no cover
-                    sentsofar = 0
-                    left = len(s)
-                    while left > 0:
-                        sent = self.sock.send(s[sentsofar:])
-                        sentsofar = sentsofar + sent
-                        left = left - sent
-            except socket.error: #pragma: no cover
+                self.sock.sendall(s)
+            except OSError: #pragma: no cover
                 self.sock.close()
                 self.sock = None  # so we can call createSocket next time
 
@@ -607,9 +589,7 @@ class SocketHandler(logging.Handler):
         try:
             s = self.makePickle(record)
             self.send(s)
-        except (KeyboardInterrupt, SystemExit): #pragma: no cover
-            raise
-        except:
+        except Exception:
             self.handleError(record)
 
     def close(self):
@@ -795,7 +775,7 @@ class SysLogHandler(logging.Handler):
         self.socket = socket.socket(socket.AF_UNIX, self.socktype)
         try:
             self.socket.connect(address)
-        except socket.error:
+        except OSError:
             self.socket.close()
             raise
 
@@ -862,16 +842,14 @@ class SysLogHandler(logging.Handler):
             if self.unixsocket:
                 try:
                     self.socket.send(msg)
-                except socket.error:
+                except OSError:
                     self._connect_unixsocket(self.address)
                     self.socket.send(msg)
             elif self.socktype == socket.SOCK_DGRAM:
                 self.socket.sendto(msg, self.address)
             else:
                 self.socket.sendall(msg)
-        except (KeyboardInterrupt, SystemExit): #pragma: no cover
-            raise
-        except:
+        except Exception:
             self.handleError(record)
 
 class SMTPHandler(logging.Handler):
@@ -949,9 +927,7 @@ class SMTPHandler(logging.Handler):
                 smtp.login(self.username, self.password)
             smtp.sendmail(self.fromaddr, self.toaddrs, msg)
             smtp.quit()
-        except (KeyboardInterrupt, SystemExit): #pragma: no cover
-            raise
-        except:
+        except Exception:
             self.handleError(record)
 
 class NTEventLogHandler(logging.Handler):
@@ -1036,9 +1012,7 @@ class NTEventLogHandler(logging.Handler):
                 type = self.getEventType(record)
                 msg = self.format(record)
                 self._welu.ReportEvent(self.appname, id, cat, type, [msg])
-            except (KeyboardInterrupt, SystemExit): #pragma: no cover
-                raise
-            except:
+            except Exception:
                 self.handleError(record)
 
     def close(self):
@@ -1123,9 +1097,7 @@ class HTTPHandler(logging.Handler):
             if self.method == "POST":
                 h.send(data.encode('utf-8'))
             h.getresponse()    #can't do anything with the result
-        except (KeyboardInterrupt, SystemExit): #pragma: no cover
-            raise
-        except:
+        except Exception:
             self.handleError(record)
 
 class BufferingHandler(logging.Handler):
@@ -1305,9 +1277,7 @@ class QueueHandler(logging.Handler):
         """
         try:
             self.enqueue(self.prepare(record))
-        except (KeyboardInterrupt, SystemExit): #pragma: no cover
-            raise
-        except:
+        except Exception:
             self.handleError(record)
 
 if threading:
diff --git a/Lib/lzma.py b/Lib/lzma.py
index 1a1b065..b2e2f7e 100644
--- a/Lib/lzma.py
+++ b/Lib/lzma.py
@@ -55,7 +55,7 @@ class LZMAFile(io.BufferedIOBase):
         be an existing file object to read from or write to.
 
         mode can be "r" for reading (default), "w" for (over)writing, or
-        "a" for appending. These can equivalently be given as "rb", "wb",
+        "a" for appending. These can equivalently be given as "rb", "wb"
         and "ab" respectively.
 
         format specifies the container format to use for the file.
@@ -110,7 +110,8 @@ class LZMAFile(io.BufferedIOBase):
             # stream will need a separate decompressor object.
             self._init_args = {"format":format, "filters":filters}
             self._decompressor = LZMADecompressor(**self._init_args)
-            self._buffer = None
+            self._buffer = b""
+            self._buffer_offset = 0
         elif mode in ("w", "wb", "a", "ab"):
             if format is None:
                 format = FORMAT_XZ
@@ -143,7 +144,7 @@ class LZMAFile(io.BufferedIOBase):
         try:
             if self._mode in (_MODE_READ, _MODE_READ_EOF):
                 self._decompressor = None
-                self._buffer = None
+                self._buffer = b""
             elif self._mode == _MODE_WRITE:
                 self._fp.write(self._compressor.flush())
                 self._compressor = None
@@ -187,15 +188,18 @@ class LZMAFile(io.BufferedIOBase):
             raise ValueError("I/O operation on closed file")
 
     def _check_can_read(self):
-        if not self.readable():
+        if self._mode not in (_MODE_READ, _MODE_READ_EOF):
+            self._check_not_closed()
             raise io.UnsupportedOperation("File not open for reading")
 
     def _check_can_write(self):
-        if not self.writable():
+        if self._mode != _MODE_WRITE:
+            self._check_not_closed()
             raise io.UnsupportedOperation("File not open for writing")
 
     def _check_can_seek(self):
-        if not self.readable():
+        if self._mode not in (_MODE_READ, _MODE_READ_EOF):
+            self._check_not_closed()
             raise io.UnsupportedOperation("Seeking is only supported "
                                           "on files open for reading")
         if not self._fp.seekable():
@@ -204,16 +208,13 @@ class LZMAFile(io.BufferedIOBase):
 
     # Fill the readahead buffer if it is empty. Returns False on EOF.
     def _fill_buffer(self):
+        if self._mode == _MODE_READ_EOF:
+            return False
         # Depending on the input data, our call to the decompressor may not
         # return any data. In this case, try again after reading another block.
-        while True:
-            if self._buffer:
-                return True
-
-            if self._decompressor.unused_data:
-                rawblock = self._decompressor.unused_data
-            else:
-                rawblock = self._fp.read(_BUFFER_SIZE)
+        while self._buffer_offset == len(self._buffer):
+            rawblock = (self._decompressor.unused_data or
+                        self._fp.read(_BUFFER_SIZE))
 
             if not rawblock:
                 if self._decompressor.eof:
@@ -229,30 +230,48 @@ class LZMAFile(io.BufferedIOBase):
                 self._decompressor = LZMADecompressor(**self._init_args)
 
             self._buffer = self._decompressor.decompress(rawblock)
+            self._buffer_offset = 0
+        return True
 
     # Read data until EOF.
     # If return_data is false, consume the data without returning it.
     def _read_all(self, return_data=True):
+        # The loop assumes that _buffer_offset is 0. Ensure that this is true.
+        self._buffer = self._buffer[self._buffer_offset:]
+        self._buffer_offset = 0
+
         blocks = []
         while self._fill_buffer():
             if return_data:
                 blocks.append(self._buffer)
             self._pos += len(self._buffer)
-            self._buffer = None
+            self._buffer = b""
         if return_data:
             return b"".join(blocks)
 
     # Read a block of up to n bytes.
     # If return_data is false, consume the data without returning it.
     def _read_block(self, n, return_data=True):
+        # If we have enough data buffered, return immediately.
+        end = self._buffer_offset + n
+        if end <= len(self._buffer):
+            data = self._buffer[self._buffer_offset : end]
+            self._buffer_offset = end
+            self._pos += len(data)
+            return data if return_data else None
+
+        # The loop assumes that _buffer_offset is 0. Ensure that this is true.
+        self._buffer = self._buffer[self._buffer_offset:]
+        self._buffer_offset = 0
+
         blocks = []
         while n > 0 and self._fill_buffer():
             if n < len(self._buffer):
                 data = self._buffer[:n]
-                self._buffer = self._buffer[n:]
+                self._buffer_offset = n
             else:
                 data = self._buffer
-                self._buffer = None
+                self._buffer = b""
             if return_data:
                 blocks.append(data)
             self._pos += len(data)
@@ -267,9 +286,9 @@ class LZMAFile(io.BufferedIOBase):
         The exact number of bytes returned is unspecified.
         """
         self._check_can_read()
-        if self._mode == _MODE_READ_EOF or not self._fill_buffer():
+        if not self._fill_buffer():
             return b""
-        return self._buffer
+        return self._buffer[self._buffer_offset:]
 
     def read(self, size=-1):
         """Read up to size uncompressed bytes from the file.
@@ -278,7 +297,7 @@ class LZMAFile(io.BufferedIOBase):
         Returns b"" if the file is already at EOF.
         """
         self._check_can_read()
-        if self._mode == _MODE_READ_EOF or size == 0:
+        if size == 0:
             return b""
         elif size < 0:
             return self._read_all()
@@ -295,18 +314,40 @@ class LZMAFile(io.BufferedIOBase):
         # this does not give enough data for the decompressor to make progress.
         # In this case we make multiple reads, to avoid returning b"".
         self._check_can_read()
-        if (size == 0 or self._mode == _MODE_READ_EOF or
-            not self._fill_buffer()):
+        if (size == 0 or
+            # Only call _fill_buffer() if the buffer is actually empty.
+            # This gives a significant speedup if *size* is small.
+            (self._buffer_offset == len(self._buffer) and not self._fill_buffer())):
             return b""
-        if 0 < size < len(self._buffer):
-            data = self._buffer[:size]
-            self._buffer = self._buffer[size:]
+        if size > 0:
+            data = self._buffer[self._buffer_offset :
+                                self._buffer_offset + size]
+            self._buffer_offset += len(data)
         else:
-            data = self._buffer
-            self._buffer = None
+            data = self._buffer[self._buffer_offset:]
+            self._buffer = b""
+            self._buffer_offset = 0
         self._pos += len(data)
         return data
 
+    def readline(self, size=-1):
+        """Read a line of uncompressed bytes from the file.
+
+        The terminating newline (if present) is retained. If size is
+        non-negative, no more than size bytes will be read (in which
+        case the line may be incomplete). Returns b'' if already at EOF.
+        """
+        self._check_can_read()
+        # Shortcut for the common case - the whole line is in the buffer.
+        if size < 0:
+            end = self._buffer.find(b"\n", self._buffer_offset) + 1
+            if end > 0:
+                line = self._buffer[self._buffer_offset : end]
+                self._buffer_offset = end
+                self._pos += len(line)
+                return line
+        return io.BufferedIOBase.readline(self, size)
+
     def write(self, data):
         """Write a bytes object to the file.
 
@@ -326,7 +367,8 @@ class LZMAFile(io.BufferedIOBase):
         self._mode = _MODE_READ
         self._pos = 0
         self._decompressor = LZMADecompressor(**self._init_args)
-        self._buffer = None
+        self._buffer = b""
+        self._buffer_offset = 0
 
     def seek(self, offset, whence=0):
         """Change the file position.
@@ -365,8 +407,7 @@ class LZMAFile(io.BufferedIOBase):
             offset -= self._pos
 
         # Read and discard data until we reach the desired position.
-        if self._mode != _MODE_READ_EOF:
-            self._read_block(offset, return_data=False)
+        self._read_block(offset, return_data=False)
 
         return self._pos
 
@@ -381,23 +422,24 @@ def open(filename, mode="rb", *,
          encoding=None, errors=None, newline=None):
     """Open an LZMA-compressed file in binary or text mode.
 
-    filename can be either an actual file name (given as a str or bytes object),
-    in which case the named file is opened, or it can be an existing file object
-    to read from or write to.
+    filename can be either an actual file name (given as a str or bytes
+    object), in which case the named file is opened, or it can be an
+    existing file object to read from or write to.
 
-    The mode argument can be "r", "rb" (default), "w", "wb", "a", or "ab" for
-    binary mode, or "rt", "wt" or "at" for text mode.
+    The mode argument can be "r", "rb" (default), "w", "wb", "a" or "ab"
+    for binary mode, or "rt", "wt" or "at" for text mode.
 
-    The format, check, preset and filters arguments specify the compression
-    settings, as for LZMACompressor, LZMADecompressor and LZMAFile.
+    The format, check, preset and filters arguments specify the
+    compression settings, as for LZMACompressor, LZMADecompressor and
+    LZMAFile.
 
-    For binary mode, this function is equivalent to the LZMAFile constructor:
-    LZMAFile(filename, mode, ...). In this case, the encoding, errors and
-    newline arguments must not be provided.
+    For binary mode, this function is equivalent to the LZMAFile
+    constructor: LZMAFile(filename, mode, ...). In this case, the
+    encoding, errors and newline arguments must not be provided.
 
     For text mode, a LZMAFile object is created, and wrapped in an
-    io.TextIOWrapper instance with the specified encoding, error handling
-    behavior, and line ending(s).
+    io.TextIOWrapper instance with the specified encoding, error
+    handling behavior, and line ending(s).
 
     """
     if "t" in mode:
@@ -427,7 +469,7 @@ def compress(data, format=FORMAT_XZ, check=-1, preset=None, filters=None):
     Refer to LZMACompressor's docstring for a description of the
     optional arguments *format*, *check*, *preset* and *filters*.
 
-    For incremental compression, use an LZMACompressor object instead.
+    For incremental compression, use an LZMACompressor instead.
     """
     comp = LZMACompressor(format, check, preset, filters)
     return comp.compress(data) + comp.flush()
@@ -439,7 +481,7 @@ def decompress(data, format=FORMAT_AUTO, memlimit=None, filters=None):
     Refer to LZMADecompressor's docstring for a description of the
     optional arguments *format*, *check* and *filters*.
 
-    For incremental decompression, use a LZMADecompressor object instead.
+    For incremental decompression, use an LZMADecompressor instead.
     """
     results = []
     while True:
diff --git a/Lib/macpath.py b/Lib/macpath.py
index 1615d91..d34f9e94 100644
--- a/Lib/macpath.py
+++ b/Lib/macpath.py
@@ -127,7 +127,7 @@ def lexists(path):
 
     try:
         st = os.lstat(path)
-    except os.error:
+    except OSError:
         return False
     return True
 
diff --git a/Lib/mailbox.py b/Lib/mailbox.py
index d3bf3fd..6d320ed 100644
--- a/Lib/mailbox.py
+++ b/Lib/mailbox.py
@@ -22,9 +22,6 @@ import email.generator
 import io
 import contextlib
 try:
-    if sys.platform == 'os2emx':
-        # OS/2 EMX fcntl() not adequate
-        raise ImportError
     import fcntl
 except ImportError:
     fcntl = None
@@ -588,7 +585,7 @@ class _singlefileMailbox(Mailbox):
         Mailbox.__init__(self, path, factory, create)
         try:
             f = open(self._path, 'rb+')
-        except IOError as e:
+        except OSError as e:
             if e.errno == errno.ENOENT:
                 if create:
                     f = open(self._path, 'wb+')
@@ -631,8 +628,7 @@ class _singlefileMailbox(Mailbox):
     def iterkeys(self):
         """Return an iterator over keys."""
         self._lookup()
-        for key in self._toc.keys():
-            yield key
+        yield from self._toc.keys()
 
     def __contains__(self, key):
         """Return True if the keyed message exists, False otherwise."""
@@ -711,8 +707,7 @@ class _singlefileMailbox(Mailbox):
         try:
             os.rename(new_file.name, self._path)
         except OSError as e:
-            if e.errno == errno.EEXIST or \
-              (os.name == 'os2' and e.errno == errno.EACCES):
+            if e.errno == errno.EEXIST:
                 os.remove(self._path)
                 os.rename(new_file.name, self._path)
             else:
@@ -993,7 +988,7 @@ class MH(Mailbox):
         path = os.path.join(self._path, str(key))
         try:
             f = open(path, 'rb+')
-        except IOError as e:
+        except OSError as e:
             if e.errno == errno.ENOENT:
                 raise KeyError('No message with key: %s' % key)
             else:
@@ -1007,7 +1002,7 @@ class MH(Mailbox):
         path = os.path.join(self._path, str(key))
         try:
             f = open(path, 'rb+')
-        except IOError as e:
+        except OSError as e:
             if e.errno == errno.ENOENT:
                 raise KeyError('No message with key: %s' % key)
             else:
@@ -1033,7 +1028,7 @@ class MH(Mailbox):
                 f = open(os.path.join(self._path, str(key)), 'rb+')
             else:
                 f = open(os.path.join(self._path, str(key)), 'rb')
-        except IOError as e:
+        except OSError as e:
             if e.errno == errno.ENOENT:
                 raise KeyError('No message with key: %s' % key)
             else:
@@ -1060,7 +1055,7 @@ class MH(Mailbox):
                 f = open(os.path.join(self._path, str(key)), 'rb+')
             else:
                 f = open(os.path.join(self._path, str(key)), 'rb')
-        except IOError as e:
+        except OSError as e:
             if e.errno == errno.ENOENT:
                 raise KeyError('No message with key: %s' % key)
             else:
@@ -1080,7 +1075,7 @@ class MH(Mailbox):
         """Return a file-like representation or raise a KeyError."""
         try:
             f = open(os.path.join(self._path, str(key)), 'rb')
-        except IOError as e:
+        except OSError as e:
             if e.errno == errno.ENOENT:
                 raise KeyError('No message with key: %s' % key)
             else:
@@ -2073,7 +2068,7 @@ def _lock_file(f, dotlock=True):
         if fcntl:
             try:
                 fcntl.lockf(f, fcntl.LOCK_EX | fcntl.LOCK_NB)
-            except IOError as e:
+            except OSError as e:
                 if e.errno in (errno.EAGAIN, errno.EACCES, errno.EROFS):
                     raise ExternalClashError('lockf: lock unavailable: %s' %
                                              f.name)
@@ -2083,7 +2078,7 @@ def _lock_file(f, dotlock=True):
             try:
                 pre_lock = _create_temporary(f.name + '.lock')
                 pre_lock.close()
-            except IOError as e:
+            except OSError as e:
                 if e.errno in (errno.EACCES, errno.EROFS):
                     return  # Without write access, just skip dotlocking.
                 else:
@@ -2097,8 +2092,7 @@ def _lock_file(f, dotlock=True):
                     os.rename(pre_lock.name, f.name + '.lock')
                     dotlock_done = True
             except OSError as e:
-                if e.errno == errno.EEXIST or \
-                  (os.name == 'os2' and e.errno == errno.EACCES):
+                if e.errno == errno.EEXIST:
                     os.remove(pre_lock.name)
                     raise ExternalClashError('dot lock unavailable: %s' %
                                              f.name)
diff --git a/Lib/mailcap.py b/Lib/mailcap.py
index 99f4958..bd61b0b 100644
--- a/Lib/mailcap.py
+++ b/Lib/mailcap.py
@@ -20,7 +20,7 @@ def getcaps():
     for mailcap in listmailcapfiles():
         try:
             fp = open(mailcap, 'r')
-        except IOError:
+        except OSError:
             continue
         morecaps = readmailcapfile(fp)
         fp.close()
diff --git a/Lib/mimetypes.py b/Lib/mimetypes.py
index 3f0bd0e..5aaa908 100644
--- a/Lib/mimetypes.py
+++ b/Lib/mimetypes.py
@@ -243,7 +243,7 @@ class MimeTypes:
             while True:
                 try:
                     ctype = _winreg.EnumKey(mimedb, i)
-                except EnvironmentError:
+                except OSError:
                     break
                 else:
                     yield ctype
@@ -256,7 +256,7 @@ class MimeTypes:
                     with _winreg.OpenKey(mimedb, ctype) as key:
                         suffix, datatype = _winreg.QueryValueEx(key,
                                                                 'Extension')
-                except EnvironmentError:
+                except OSError:
                     continue
                 if datatype != _winreg.REG_SZ:
                     continue
@@ -359,7 +359,7 @@ def init(files=None):
 def read_mime_types(file):
     try:
         f = open(file)
-    except IOError:
+    except OSError:
         return None
     db = MimeTypes()
     db.readfp(f, True)
@@ -378,12 +378,14 @@ def _default_mime_types():
         '.taz': '.tar.gz',
         '.tz': '.tar.gz',
         '.tbz2': '.tar.bz2',
+        '.txz': '.tar.xz',
         }
 
     encodings_map = {
         '.gz': 'gzip',
         '.Z': 'compress',
         '.bz2': 'bzip2',
+        '.xz': 'xz',
         }
 
     # Before adding new types, make sure they are either registered with IANA,
diff --git a/Lib/modulefinder.py b/Lib/modulefinder.py
index f90a432..4996d7a 100644
--- a/Lib/modulefinder.py
+++ b/Lib/modulefinder.py
@@ -229,7 +229,7 @@ class ModuleFinder:
         for dir in m.__path__:
             try:
                 names = os.listdir(dir)
-            except os.error:
+            except OSError:
                 self.msg(2, "can't list directory", dir)
                 continue
             for name in names:
diff --git a/Lib/multiprocessing/__init__.py b/Lib/multiprocessing/__init__.py
index 1f3e67c..b5f16d7 100644
--- a/Lib/multiprocessing/__init__.py
+++ b/Lib/multiprocessing/__init__.py
@@ -8,10 +8,6 @@
 # subpackage 'multiprocessing.dummy' has the same API but is a simple
 # wrapper for 'threading'.
 #
-# Try calling `multiprocessing.doc.main()` to read the html
-# documentation in a webbrowser.
-#
-#
 # Copyright (c) 2006-2008, R Oudkerk
 # Licensed to PSF under a Contributor Agreement.
 #
@@ -27,8 +23,6 @@ __all__ = [
     'Value', 'Array', 'RawValue', 'RawArray', 'SUBDEBUG', 'SUBWARNING',
     ]
 
-__author__ = 'R. Oudkerk (r.m.oudkerk@gmail.com)'
-
 #
 # Imports
 #
@@ -40,6 +34,13 @@ from multiprocessing.process import Process, current_process, active_children
 from multiprocessing.util import SUBDEBUG, SUBWARNING
 
 #
+# Alias for main module -- will be reset by bootstrapping child processes
+#
+
+if '__main__' in sys.modules:
+    sys.modules['__mp_main__'] = sys.modules['__main__']
+
+#
 # Exceptions
 #
 
diff --git a/Lib/multiprocessing/connection.py b/Lib/multiprocessing/connection.py
index 1d65f46..9a357f6 100644
--- a/Lib/multiprocessing/connection.py
+++ b/Lib/multiprocessing/connection.py
@@ -132,22 +132,22 @@ class _ConnectionBase:
 
     def _check_closed(self):
         if self._handle is None:
-            raise IOError("handle is closed")
+            raise OSError("handle is closed")
 
     def _check_readable(self):
         if not self._readable:
-            raise IOError("connection is write-only")
+            raise OSError("connection is write-only")
 
     def _check_writable(self):
         if not self._writable:
-            raise IOError("connection is read-only")
+            raise OSError("connection is read-only")
 
     def _bad_message_length(self):
         if self._writable:
             self._readable = False
         else:
             self.close()
-        raise IOError("bad message length")
+        raise OSError("bad message length")
 
     @property
     def closed(self):
@@ -317,7 +317,7 @@ if _winapi:
                             return f
                         elif err == _winapi.ERROR_MORE_DATA:
                             return self._get_more_data(ov, maxsize)
-                except IOError as e:
+                except OSError as e:
                     if e.winerror == _winapi.ERROR_BROKEN_PIPE:
                         raise EOFError
                     else:
@@ -383,7 +383,7 @@ class Connection(_ConnectionBase):
                 if remaining == size:
                     raise EOFError
                 else:
-                    raise IOError("got end of file during message")
+                    raise OSError("got end of file during message")
             buf.write(chunk)
             remaining -= n
         return buf
@@ -443,7 +443,7 @@ class Listener(object):
         Returns a `Connection` object.
         '''
         if self._listener is None:
-            raise IOError('listener is closed')
+            raise OSError('listener is closed')
         c = self._listener.accept()
         if self._authkey:
             deliver_challenge(c, self._authkey)
@@ -676,7 +676,7 @@ if sys.platform == 'win32':
                     0, _winapi.NULL, _winapi.OPEN_EXISTING,
                     _winapi.FILE_FLAG_OVERLAPPED, _winapi.NULL
                     )
-            except WindowsError as e:
+            except OSError as e:
                 if e.winerror not in (_winapi.ERROR_SEM_TIMEOUT,
                                       _winapi.ERROR_PIPE_BUSY) or _check_timeout(t):
                     raise
diff --git a/Lib/multiprocessing/dummy/__init__.py b/Lib/multiprocessing/dummy/__init__.py
index e31fc61..20ae957 100644
--- a/Lib/multiprocessing/dummy/__init__.py
+++ b/Lib/multiprocessing/dummy/__init__.py
@@ -4,32 +4,7 @@
 # multiprocessing/dummy/__init__.py
 #
 # Copyright (c) 2006-2008, R Oudkerk
-# All rights reserved.
-#
-# Redistribution and use in source and binary forms, with or without
-# modification, are permitted provided that the following conditions
-# are met:
-#
-# 1. Redistributions of source code must retain the above copyright
-#    notice, this list of conditions and the following disclaimer.
-# 2. Redistributions in binary form must reproduce the above copyright
-#    notice, this list of conditions and the following disclaimer in the
-#    documentation and/or other materials provided with the distribution.
-# 3. Neither the name of author nor the names of any contributors may be
-#    used to endorse or promote products derived from this software
-#    without specific prior written permission.
-#
-# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS "AS IS" AND
-# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
-# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
-# ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
-# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
-# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
-# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
-# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
-# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
-# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
-# SUCH DAMAGE.
+# Licensed to PSF under a Contributor Agreement.
 #
 
 __all__ = [
diff --git a/Lib/multiprocessing/dummy/connection.py b/Lib/multiprocessing/dummy/connection.py
index 874ec8e..694ef96 100644
--- a/Lib/multiprocessing/dummy/connection.py
+++ b/Lib/multiprocessing/dummy/connection.py
@@ -4,32 +4,7 @@
 # multiprocessing/dummy/connection.py
 #
 # Copyright (c) 2006-2008, R Oudkerk
-# All rights reserved.
-#
-# Redistribution and use in source and binary forms, with or without
-# modification, are permitted provided that the following conditions
-# are met:
-#
-# 1. Redistributions of source code must retain the above copyright
-#    notice, this list of conditions and the following disclaimer.
-# 2. Redistributions in binary form must reproduce the above copyright
-#    notice, this list of conditions and the following disclaimer in the
-#    documentation and/or other materials provided with the distribution.
-# 3. Neither the name of author nor the names of any contributors may be
-#    used to endorse or promote products derived from this software
-#    without specific prior written permission.
-#
-# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS "AS IS" AND
-# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
-# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
-# ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
-# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
-# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
-# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
-# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
-# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
-# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
-# SUCH DAMAGE.
+# Licensed to PSF under a Contributor Agreement.
 #
 
 __all__ = [ 'Client', 'Listener', 'Pipe' ]
diff --git a/Lib/multiprocessing/forking.py b/Lib/multiprocessing/forking.py
index c5501a2..d3e7a10 100644
--- a/Lib/multiprocessing/forking.py
+++ b/Lib/multiprocessing/forking.py

path: root/generic/tclPkg.c

/*
 * tclPkg.c --
 *
 *	This file implements package and version control for Tcl via the
 *	"package" command and a few C APIs.
 *
 * Copyright (c) 1996 Sun Microsystems, Inc.
 * Copyright (c) 2006 Andreas Kupries <andreas_kupries@users.sourceforge.net>
 *
 * See the file "license.terms" for information on usage and redistribution of
 * this file, and for a DISCLAIMER OF ALL WARRANTIES.
 *
 * TIP #268.
 * Heavily rewritten to handle the extend version numbers, and extended
 * package requirements.
 */

#include "tclInt.h"

/*
 * Each invocation of the "package ifneeded" command creates a structure of
 * the following type, which is used to load the package into the interpreter
 * if it is requested with a "package require" command.
 */

typedef struct PkgAvail {
    char *version;		/* Version string; malloc'ed. */
    char *script;		/* Script to invoke to provide this version of
				 * the package. Malloc'ed and protected by
				 * Tcl_Preserve and Tcl_Release. */
    struct PkgAvail *nextPtr;	/* Next in list of available versions of the
				 * same package. */
} PkgAvail;

/*
 * For each package that is known in any way to an interpreter, there is one
 * record of the following type. These records are stored in the
 * "packageTable" hash table in the interpreter, keyed by package name such as
 * "Tk" (no version number).
 */

typedef struct Package {
    char *version;		/* Version that has been supplied in this
				 * interpreter via "package provide"
				 * (malloc'ed). NULL means the package doesn't
				 * exist in this interpreter yet. */
    PkgAvail *availPtr;		/* First in list of all available versions of
				 * this package. */
    ClientData clientData;	/* Client data. */
} Package;

/*
 * Prototypes for functions defined in this file:
 */

static int		CheckVersionAndConvert(Tcl_Interp *interp,
			    const char *string, char **internal, int *stable);
static int		CompareVersions(char *v1i, char *v2i,
			    int *isMajorPtr);
static int		CheckRequirement(Tcl_Interp *interp,
			    const char *string);
static int		CheckAllRequirements(Tcl_Interp *interp, int reqc,
			    Tcl_Obj *const reqv[]);
static int		RequirementSatisfied(char *havei, const char *req);
static int		SomeRequirementSatisfied(char *havei, int reqc,
			    Tcl_Obj *const reqv[]);
static void		AddRequirementsToResult(Tcl_Interp *interp, int reqc,
			    Tcl_Obj *const reqv[]);
static void		AddRequirementsToDString(Tcl_DString *dstring,
			    int reqc, Tcl_Obj *const reqv[]);
static Package *	FindPackage(Tcl_Interp *interp, const char *name);
static const char *	PkgRequireCore(Tcl_Interp *interp, const char *name,
			    int reqc, Tcl_Obj *const reqv[],
			    ClientData *clientDataPtr);

/*
 * Helper macros.
 */

#define DupBlock(v,s,len) \
    ((v) = ckalloc(len), memcpy((v),(s),(len)))
#define DupString(v,s) \
    do { \
	unsigned local__len = (unsigned) (strlen(s) + 1); \
	DupBlock((v),(s),local__len); \
    } while (0)

/*
 *----------------------------------------------------------------------
 *
 * Tcl_PkgProvide / Tcl_PkgProvideEx --
 *
 *	This function is invoked to declare that a particular version of a
 *	particular package is now present in an interpreter. There must not be
 *	any other version of this package already provided in the interpreter.
 *
 * Results:
 *	Normally returns TCL_OK; if there is already another version of the
 *	package loaded then TCL_ERROR is returned and an error message is left
 *	in the interp's result.
 *
 * Side effects:
 *	The interpreter remembers that this package is available, so that no
 *	other version of the package may be provided for the interpreter.
 *
 *----------------------------------------------------------------------
 */

int
Tcl_PkgProvide(
    Tcl_Interp *interp,		/* Interpreter in which package is now
				 * available. */
    const char *name,		/* Name of package. */
    const char *version)	/* Version string for package. */
{
    return Tcl_PkgProvideEx(interp, name, version, NULL);
}

int
Tcl_PkgProvideEx(
    Tcl_Interp *interp,		/* Interpreter in which package is now
				 * available. */
    const char *name,		/* Name of package. */
    const char *version,	/* Version string for package. */
    ClientData clientData)	/* clientdata for this package (normally used
				 * for C callback function table) */
{
    Package *pkgPtr;
    char *pvi, *vi;
    int res;

    pkgPtr = FindPackage(interp, name);
    if (pkgPtr->version == NULL) {
	DupString(pkgPtr->version, version);
	pkgPtr->clientData = clientData;
	return TCL_OK;
    }

    if (CheckVersionAndConvert(interp, pkgPtr->version, &pvi,
	    NULL) != TCL_OK) {
	return TCL_ERROR;
    } else if (CheckVersionAndConvert(interp, version, &vi, NULL) != TCL_OK) {
	ckfree(pvi);
	return TCL_ERROR;
    }

    res = CompareVersions(pvi, vi, NULL);
    ckfree(pvi);
    ckfree(vi);

    if (res == 0) {
	if (clientData != NULL) {
	    pkgPtr->clientData = clientData;
	}
	return TCL_OK;
    }
    Tcl_AppendResult(interp, "conflicting versions provided for package \"",
	    name, "\": ", pkgPtr->version, ", then ", version, NULL);
    return TCL_ERROR;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_PkgRequire / Tcl_PkgRequireEx / Tcl_PkgRequireProc --
 *
 *	This function is called by code that depends on a particular version
 *	of a particular package. If the package is not already provided in the
 *	interpreter, this function invokes a Tcl script to provide it. If the
 *	package is already provided, this function makes sure that the
 *	caller's needs don't conflict with the version that is present.
 *
 * Results:
 *	If successful, returns the version string for the currently provided
 *	version of the package, which may be different from the "version"
 *	argument. If the caller's requirements cannot be met (e.g. the version
 *	requested conflicts with a currently provided version, or the required
 *	version cannot be found, or the script to provide the required version
 *	generates an error), NULL is returned and an error message is left in
 *	the interp's result.
 *
 * Side effects:
 *	The script from some previous "package ifneeded" command may be
 *	invoked to provide the package.
 *
 *----------------------------------------------------------------------
 */

const char *
Tcl_PkgRequire(
    Tcl_Interp *interp,		/* Interpreter in which package is now
				 * available. */
    const char *name,		/* Name of desired package. */
    const char *version,	/* Version string for desired version; NULL
				 * means use the latest version available. */
    int exact)			/* Non-zero means that only the particular
				 * version given is acceptable. Zero means use
				 * the latest compatible version. */
{
    return Tcl_PkgRequireEx(interp, name, version, exact, NULL);
}

const char *
Tcl_PkgRequireEx(
    Tcl_Interp *interp,		/* Interpreter in which package is now
				 * available. */
    const char *name,		/* Name of desired package. */
    const char *version,	/* Version string for desired version; NULL
				 * means use the latest version available. */
    int exact,			/* Non-zero means that only the particular
				 * version given is acceptable. Zero means use
				 * the latest compatible version. */
    ClientData *clientDataPtr)	/* Used to return the client data for this
				 * package. If it is NULL then the client data
				 * is not returned. This is unchanged if this
				 * call fails for any reason. */
{
    Tcl_Obj *ov;
    const char *result = NULL;

    /*
     * If an attempt is being made to load this into a standalone executable
     * on a platform where backlinking is not supported then this must be a
     * shared version of Tcl (Otherwise the load would have failed). Detect
     * this situation by checking that this library has been correctly
     * initialised. If it has not been then return immediately as nothing will
     * work.
     */

    if (tclEmptyStringRep == NULL) {
	/*
	 * OK, so what's going on here?
	 *
	 * First, what are we doing? We are performing a check on behalf of
	 * one particular caller, Tcl_InitStubs(). When a package is stub-
	 * enabled, it is statically linked to libtclstub.a, which contains a
	 * copy of Tcl_InitStubs(). When a stub-enabled package is loaded, its
	 * *_Init() function is supposed to call Tcl_InitStubs() before
	 * calling any other functions in the Tcl library. The first Tcl
	 * function called by Tcl_InitStubs() through the stub table is
	 * Tcl_PkgRequireEx(), so this code right here is the first code that
	 * is part of the original Tcl library in the executable that gets
	 * executed on behalf of a newly loaded stub-enabled package.
	 *
	 * One easy error for the developer/builder of a stub-enabled package
	 * to make is to forget to define USE_TCL_STUBS when compiling the
	 * package. When that happens, the package will contain symbols that
	 * are references to the Tcl library, rather than function pointers
	 * referencing the stub table. On platforms that lack backlinking,
	 * those unresolved references may cause the loading of the package to
	 * also load a second copy of the Tcl library, leading to all kinds of
	 * trouble. We would like to catch that error and report a useful
	 * message back to the user. That's what we're doing.
	 *
	 * Second, how does this work? If we reach this point, then the global
	 * variable tclEmptyStringRep has the value NULL. Compare that with
	 * the definition of tclEmptyStringRep near the top of the file
	 * generic/tclObj.c. It clearly should not have the value NULL; it
	 * should point to the char tclEmptyString. If we see it having the
	 * value NULL, then somehow we are seeing a Tcl library that isn't
	 * completely initialized, and that's an indicator for the error
	 * condition described above. (Further explanation is welcome.)
	 *
	 * Third, so what do we do about it? This situation indicates the
	 * package we just loaded wasn't properly compiled to be stub-enabled,
	 * yet it thinks it is stub-enabled (it called Tcl_InitStubs()). We
	 * want to report that the package just loaded is broken, so we want
	 * to place an error message in the interpreter result and return NULL
	 * to indicate failure to Tcl_InitStubs() so that it will also fail.
	 * (Further explanation why we don't want to Tcl_Panic() is welcome.
	 * After all, two Tcl libraries can't be a good thing!)
	 *
	 * Trouble is that's going to be tricky. We're now using a Tcl library
	 * that's not fully initialized. In particular, it doesn't have a
	 * proper value for tclEmptyStringRep. The Tcl_Obj system heavily
	 * depends on the value of tclEmptyStringRep and all of Tcl depends
	 * (increasingly) on the Tcl_Obj system, we need to correct that flaw
	 * before making the calls to set the interpreter result to the error
	 * message. That's the only flaw corrected; other problems with
	 * initialization of the Tcl library are not remedied, so be very
	 * careful about adding any other calls here without checking how they
	 * behave when initialization is incomplete.
	 */

	tclEmptyStringRep = &tclEmptyString;
	Tcl_AppendResult(interp, "Cannot load package \"", name,
		"\" in standalone executable: This package is not "
		"compiled with stub support", NULL);
	return NULL;
    }

    /*
     * Translate between old and new API, and defer to the new function.
     */

    if (version == NULL) {
	result = PkgRequireCore(interp, name, 0, NULL, clientDataPtr);
    } else {
	if (exact && TCL_OK
		!= CheckVersionAndConvert(interp, version, NULL, NULL)) {
	    return NULL;
	}
	ov = Tcl_NewStringObj(version, -1);
	if (exact) {
	    Tcl_AppendStringsToObj(ov, "-", version, NULL);
	}
	Tcl_IncrRefCount(ov);
	result = PkgRequireCore(interp, name, 1, &ov, clientDataPtr);
	TclDecrRefCount(ov);
    }

    return result;
}

int
Tcl_PkgRequireProc(
    Tcl_Interp *interp,		/* Interpreter in which package is now
				 * available. */
    const char *name,		/* Name of desired package. */
    int reqc,			/* Requirements constraining the desired
				 * version. */
    Tcl_Obj *const reqv[],	/* 0 means to use the latest version
				 * available. */
    ClientData *clientDataPtr)
{
    const char *result =
	    PkgRequireCore(interp, name, reqc, reqv, clientDataPtr);

    if (result == NULL) {
	return TCL_ERROR;
    }
    Tcl_SetObjResult(interp, Tcl_NewStringObj(result, -1));
    return TCL_OK;
}

static const char *
PkgRequireCore(
    Tcl_Interp *interp,		/* Interpreter in which package is now
				 * available. */
    const char *name,		/* Name of desired package. */
    int reqc,			/* Requirements constraining the desired
				 * version. */
    Tcl_Obj *const reqv[],	/* 0 means to use the latest version
				 * available. */
    ClientData *clientDataPtr)
{
    Interp *iPtr = (Interp *) interp;
    Package *pkgPtr;
    PkgAvail *availPtr, *bestPtr, *bestStablePtr;
    char *availVersion, *bestVersion;
				/* Internal rep. of versions */
    int availStable, code, satisfies, pass;
    char *script, *pkgVersionI;
    Tcl_DString command;

    /*
     * It can take up to three passes to find the package: one pass to run the
     * "package unknown" script, one to run the "package ifneeded" script for
     * a specific version, and a final pass to lookup the package loaded by
     * the "package ifneeded" script.
     */

    for (pass=1 ;; pass++) {
	pkgPtr = FindPackage(interp, name);
	if (pkgPtr->version != NULL) {
	    break;
	}

	/*
	 * Check whether we're already attempting to load some version of this
	 * package (circular dependency detection).
	 */

	if (pkgPtr->clientData != NULL) {
	    Tcl_AppendResult(interp, "circular package dependency: "
		    "attempt to provide ", name, " ",
		    (char *) pkgPtr->clientData, " requires ", name, NULL);
	    AddRequirementsToResult(interp, reqc, reqv);
	    return NULL;
	}

	/*
	 * The package isn't yet present. Search the list of available
	 * versions and invoke the script for the best available version. We
	 * are actually locating the best, and the best stable version. One of
	 * them is then chosen based on the selection mode.
	 */

	bestPtr = NULL;
	bestStablePtr = NULL;
	bestVersion = NULL;

	for (availPtr = pkgPtr->availPtr; availPtr != NULL;
		availPtr = availPtr->nextPtr) {
	    if (CheckVersionAndConvert(interp, availPtr->version,
		    &availVersion, &availStable) != TCL_OK) {
		/*
		 * The provided version number has invalid syntax. This
		 * should not happen. This should have been caught by the
		 * 'package ifneeded' registering the package.
		 */

		continue;
	    }

	    if (bestPtr != NULL) {
		int res = CompareVersions(availVersion, bestVersion, NULL);

		/*
		 * Note: Use internal reps!
		 */

		if (res <= 0) {
		    /*
		     * The version of the package sought is not as good as the
		     * currently selected version. Ignore it.
		     */

		    ckfree(availVersion);
		    availVersion = NULL;
		    continue;
		}
	    }

	    /* We have found a version which is better than our max. */

	    if (reqc > 0) {
		/* Check satisfaction of requirements. */

		satisfies = SomeRequirementSatisfied(availVersion, reqc, reqv);
		if (!satisfies) {
		    ckfree(availVersion);
		    availVersion = NULL;
		    continue;
		}
	    }

	    bestPtr = availPtr;

	    if (bestVersion != NULL) {
		ckfree(bestVersion);
	    }
	    bestVersion = availVersion;

	    /*
	     * If this new best version is stable then it also has to be
	     * better than the max stable version found so far.
	     */

	    if (availStable) {
		bestStablePtr = availPtr;
	    }
	}

	if (bestVersion != NULL) {
	    ckfree(bestVersion);
	}

	/*
	 * Now choose a version among the two best. For 'latest' we simply
	 * take (actually keep) the best. For 'stable' we take the best
	 * stable, if there is any, or the best if there is nothing stable.
	 */

	if ((iPtr->packagePrefer == PKG_PREFER_STABLE)
		&& (bestStablePtr != NULL)) {
	    bestPtr = bestStablePtr;
	}

	if (bestPtr != NULL) {
	    /*
	     * We found an ifneeded script for the package. Be careful while
	     * executing it: this could cause reentrancy, so (a) protect the
	     * script itself from deletion and (b) don't assume that bestPtr
	     * will still exist when the script completes.
	     */

	    const char *versionToProvide = bestPtr->version;
	    script = bestPtr->script;

	    pkgPtr->clientData = (ClientData) versionToProvide;
	    Tcl_Preserve((ClientData) script);
	    Tcl_Preserve((ClientData) versionToProvide);
	    code = Tcl_EvalEx(interp, script, -1, TCL_EVAL_GLOBAL);
	    Tcl_Release((ClientData) script);

	    pkgPtr = FindPackage(interp, name);
	    if (code == TCL_OK) {
		Tcl_ResetResult(interp);
		if (pkgPtr->version == NULL) {
		    code = TCL_ERROR;
		    Tcl_AppendResult(interp, "attempt to provide package ",
			    name, " ", versionToProvide,
			    " failed: no version of package ", name,
			    " provided", NULL);
		} else {
		    char *pvi, *vi;

		    if (CheckVersionAndConvert(interp, pkgPtr->version, &pvi,
			    NULL) != TCL_OK) {
			code = TCL_ERROR;
		    } else if (CheckVersionAndConvert(interp,
			    versionToProvide, &vi, NULL) != TCL_OK) {
			ckfree(pvi);
			code = TCL_ERROR;
		    } else {
			int res = CompareVersions(pvi, vi, NULL);

			ckfree(pvi);
			ckfree(vi);
			if (res != 0) {
			    code = TCL_ERROR;
			    Tcl_AppendResult(interp,
				    "attempt to provide package ", name, " ",
				    versionToProvide, " failed: package ",
				    name, " ", pkgPtr->version,
				    " provided instead", NULL);
			}
		    }
		}
	    } else if (code != TCL_ERROR) {
		Tcl_Obj *codePtr = Tcl_NewIntObj(code);

		Tcl_ResetResult(interp);
		Tcl_AppendResult(interp, "attempt to provide package ", name,
			" ", versionToProvide, " failed: bad return code: ",
			TclGetString(codePtr), NULL);
		TclDecrRefCount(codePtr);
		code = TCL_ERROR;
	    }

	    if (code == TCL_ERROR) {
		Tcl_AppendObjToErrorInfo(interp, Tcl_ObjPrintf(
			"\n    (\"package ifneeded %s %s\" script)",
			name, versionToProvide));
	    }
	    Tcl_Release((ClientData) versionToProvide);

	    if (code != TCL_OK) {
		/*
		 * Take a non-TCL_OK code from the script as an indication the
		 * package wasn't loaded properly, so the package system
		 * should not remember an improper load.
		 *
		 * This is consistent with our returning NULL. If we're not
		 * willing to tell our caller we got a particular version, we
		 * shouldn't store that version for telling future callers
		 * either.
		 */

		if (pkgPtr->version != NULL) {
		    ckfree(pkgPtr->version);
		    pkgPtr->version = NULL;
		}
		pkgPtr->clientData = NULL;
		return NULL;
	    }

	    break;
	}

	/*
	 * The package is not in the database. If there is a "package unknown"
	 * command, invoke it (but only on the first pass; after that, we
	 * should not get here in the first place).
	 */

	if (pass > 1) {
	    break;
	}

	script = ((Interp *) interp)->packageUnknown;
	if (script != NULL) {
	    Tcl_DStringInit(&command);
	    Tcl_DStringAppend(&command, script, -1);
	    Tcl_DStringAppendElement(&command, name);
	    AddRequirementsToDString(&command, reqc, reqv);

	    code = Tcl_EvalEx(interp, Tcl_DStringValue(&command),
		    Tcl_DStringLength(&command), TCL_EVAL_GLOBAL);
	    Tcl_DStringFree(&command);

	    if ((code != TCL_OK) && (code != TCL_ERROR)) {
		Tcl_Obj *codePtr = Tcl_NewIntObj(code);
		Tcl_ResetResult(interp);
		Tcl_AppendResult(interp, "bad return code: ",
			TclGetString(codePtr), NULL);
		Tcl_DecrRefCount(codePtr);
		code = TCL_ERROR;
	    }
	    if (code == TCL_ERROR) {
		Tcl_AddErrorInfo(interp,
			"\n    (\"package unknown\" script)");
		return NULL;
	    }
	    Tcl_ResetResult(interp);
	}
    }

    if (pkgPtr->version == NULL) {
	Tcl_AppendResult(interp, "can't find package ", name, NULL);
	AddRequirementsToResult(interp, reqc, reqv);
	return NULL;
    }

    /*
     * At this point we know that the package is present. Make sure that the
     * provided version meets the current requirements.
     */

    if (reqc == 0) {
	satisfies = 1;
    } else {
	CheckVersionAndConvert(interp, pkgPtr->version, &pkgVersionI, NULL);
	satisfies = SomeRequirementSatisfied(pkgVersionI, reqc, reqv);

	ckfree(pkgVersionI);
    }

    if (satisfies) {
	if (clientDataPtr) {
	    *clientDataPtr = pkgPtr->clientData;
	}
	return pkgPtr->version;
    }

    Tcl_AppendResult(interp, "version conflict for package \"", name,
	    "\": have ", pkgPtr->version, ", need", NULL);
    AddRequirementsToResult(interp, reqc, reqv);
    return NULL;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_PkgPresent / Tcl_PkgPresentEx --
 *
 *	Checks to see whether the specified package is present. If it is not
 *	then no additional action is taken.
 *
 * Results:
 *	If successful, returns the version string for the currently provided
 *	version of the package, which may be different from the "version"
 *	argument. If the caller's requirements cannot be met (e.g. the version
 *	requested conflicts with a currently provided version), NULL is
 *	returned and an error message is left in interp->result.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

const char *
Tcl_PkgPresent(
    Tcl_Interp *interp,		/* Interpreter in which package is now
				 * available. */
    const char *name,		/* Name of desired package. */
    const char *version,	/* Version string for desired version; NULL
				 * means use the latest version available. */
    int exact)			/* Non-zero means that only the particular
				 * version given is acceptable. Zero means use
				 * the latest compatible version. */
{
    return Tcl_PkgPresentEx(interp, name, version, exact, NULL);
}

const char *
Tcl_PkgPresentEx(
    Tcl_Interp *interp,		/* Interpreter in which package is now
				 * available. */
    const char *name,		/* Name of desired package. */
    const char *version,	/* Version string for desired version; NULL
				 * means use the latest version available. */
    int exact,			/* Non-zero means that only the particular
				 * version given is acceptable. Zero means use
				 * the latest compatible version. */
    ClientData *clientDataPtr)	/* Used to return the client data for this
				 * package. If it is NULL then the client data
				 * is not returned. This is unchanged if this
				 * call fails for any reason. */
{
    Interp *iPtr = (Interp *) interp;
    Tcl_HashEntry *hPtr;
    Package *pkgPtr;

    hPtr = Tcl_FindHashEntry(&iPtr->packageTable, name);
    if (hPtr) {
	pkgPtr = Tcl_GetHashValue(hPtr);
	if (pkgPtr->version != NULL) {
	    /*
	     * At this point we know that the package is present. Make sure
	     * that the provided version meets the current requirement by
	     * calling Tcl_PkgRequireEx() to check for us.
	     */

	    const char *foundVersion = Tcl_PkgRequireEx(interp, name, version,
		    exact, clientDataPtr);

	    if (foundVersion == NULL) {
		Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "PACKAGE", name,
			NULL);
	    }
	    return foundVersion;
	}
    }

    if (version != NULL) {
	Tcl_AppendResult(interp, "package ", name, " ", version,
		" is not present", NULL);
    } else {
	Tcl_AppendResult(interp, "package ", name, " is not present", NULL);
    }
    Tcl_SetErrorCode(interp, "TCL", "LOOKUP", "PACKAGE", name, NULL);
    return NULL;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_PackageObjCmd --
 *
 *	This function is invoked to process the "package" Tcl command. See the
 *	user documentation for details on what it does.
 *
 * Results:
 *	A standard Tcl result.
 *
 * Side effects:
 *	See the user documentation.
 *
 *----------------------------------------------------------------------
 */

	/* ARGSUSED */
int
Tcl_PackageObjCmd(
    ClientData dummy,		/* Not used. */
    Tcl_Interp *interp,		/* Current interpreter. */
    int objc,			/* Number of arguments. */
    Tcl_Obj *const objv[])	/* Argument objects. */
{
    static const char *pkgOptions[] = {
	"forget",  "ifneeded", "names",   "prefer",   "present",
	"provide", "require",  "unknown", "vcompare", "versions",
	"vsatisfies", NULL
    };
    enum pkgOptions {
	PKG_FORGET,  PKG_IFNEEDED, PKG_NAMES,   PKG_PREFER,   PKG_PRESENT,
	PKG_PROVIDE, PKG_REQUIRE,  PKG_UNKNOWN, PKG_VCOMPARE, PKG_VERSIONS,
	PKG_VSATISFIES
    };
    Interp *iPtr = (Interp *) interp;
    int optionIndex, exact, i, satisfies;
    PkgAvail *availPtr, *prevPtr;
    Package *pkgPtr;
    Tcl_HashEntry *hPtr;
    Tcl_HashSearch search;
    Tcl_HashTable *tablePtr;
    const char *version;
    char *argv2, *argv3, *argv4, *iva = NULL, *ivb = NULL;

    if (objc < 2) {
	Tcl_WrongNumArgs(interp, 1, objv, "option ?arg arg ...?");
	return TCL_ERROR;
    }

    if (Tcl_GetIndexFromObj(interp, objv[1], pkgOptions, "option", 0,
	    &optionIndex) != TCL_OK) {
	return TCL_ERROR;
    }
    switch ((enum pkgOptions) optionIndex) {
    case PKG_FORGET: {
	char *keyString;

	for (i = 2; i < objc; i++) {
	    keyString = TclGetString(objv[i]);
	    hPtr = Tcl_FindHashEntry(&iPtr->packageTable, keyString);
	    if (hPtr == NULL) {
		continue;
	    }
	    pkgPtr = Tcl_GetHashValue(hPtr);
	    Tcl_DeleteHashEntry(hPtr);
	    if (pkgPtr->version != NULL) {
		ckfree(pkgPtr->version);
	    }
	    while (pkgPtr->availPtr != NULL) {
		availPtr = pkgPtr->availPtr;
		pkgPtr->availPtr = availPtr->nextPtr;
		Tcl_EventuallyFree((ClientData)availPtr->version, TCL_DYNAMIC);
		Tcl_EventuallyFree((ClientData)availPtr->script, TCL_DYNAMIC);
		ckfree((char *) availPtr);
	    }
	    ckfree((char *) pkgPtr);
	}
	break;
    }
    case PKG_IFNEEDED: {
	int length, res;
	char *argv3i, *avi;

	if ((objc != 4) && (objc != 5)) {
	    Tcl_WrongNumArgs(interp, 2, objv, "package version ?script?");
	    return TCL_ERROR;
	}
	argv3 = TclGetString(objv[3]);
	if (CheckVersionAndConvert(interp, argv3, &argv3i, NULL) != TCL_OK) {
	    return TCL_ERROR;
	}
	argv2 = TclGetString(objv[2]);
	if (objc == 4) {
	    hPtr = Tcl_FindHashEntry(&iPtr->packageTable, argv2);
	    if (hPtr == NULL) {
		ckfree(argv3i);
		return TCL_OK;
	    }
	    pkgPtr = Tcl_GetHashValue(hPtr);
	} else {
	    pkgPtr = FindPackage(interp, argv2);
	}
	argv3 = Tcl_GetStringFromObj(objv[3], &length);

	for (availPtr = pkgPtr->availPtr, prevPtr = NULL; availPtr != NULL;
		prevPtr = availPtr, availPtr = availPtr->nextPtr) {
	    if (CheckVersionAndConvert(interp, availPtr->version, &avi,
		    NULL) != TCL_OK) {
		ckfree(argv3i);
		return TCL_ERROR;
	    }

	    res = CompareVersions(avi, argv3i, NULL);
	    ckfree(avi);

	    if (res == 0){
		if (objc == 4) {
		    ckfree(argv3i);
		    Tcl_SetResult(interp, availPtr->script, TCL_VOLATILE);
		    return TCL_OK;
		}
		Tcl_EventuallyFree((ClientData)availPtr->script, TCL_DYNAMIC);
		break;
	    }
	}
	ckfree(argv3i);

	if (objc == 4) {
	    return TCL_OK;
	}
	if (availPtr == NULL) {
	    availPtr = (PkgAvail *) ckalloc(sizeof(PkgAvail));
	    DupBlock(availPtr->version, argv3, (unsigned) length + 1);

	    if (prevPtr == NULL) {
		availPtr->nextPtr = pkgPtr->availPtr;
		pkgPtr->availPtr = availPtr;
	    } else {
		availPtr->nextPtr = prevPtr->nextPtr;
		prevPtr->nextPtr = availPtr;
	    }
	}
	argv4 = Tcl_GetStringFromObj(objv[4], &length);
	DupBlock(availPtr->script, argv4, (unsigned) length + 1);
	break;
    }
    case PKG_NAMES:
	if (objc != 2) {
	    Tcl_WrongNumArgs(interp, 2, objv, NULL);
	    return TCL_ERROR;
	}
	tablePtr = &iPtr->packageTable;
	for (hPtr = Tcl_FirstHashEntry(tablePtr, &search); hPtr != NULL;
		hPtr = Tcl_NextHashEntry(&search)) {
	    pkgPtr = Tcl_GetHashValue(hPtr);
	    if ((pkgPtr->version != NULL) || (pkgPtr->availPtr != NULL)) {
		Tcl_AppendElement(interp, Tcl_GetHashKey(tablePtr, hPtr));
	    }
	}
	break;
    case PKG_PRESENT: {
	const char *name;
	if (objc < 3) {
	    goto require;
	}
	argv2 = TclGetString(objv[2]);
	if ((argv2[0] == '-') && (strcmp(argv2, "-exact") == 0)) {
	    if (objc != 5) {
		goto requireSyntax;
	    }
	    exact = 1;
	    name = TclGetString(objv[3]);
	} else {
	    exact = 0;
	    name = argv2;
	}

	hPtr = Tcl_FindHashEntry(&iPtr->packageTable, name);
	if (hPtr != NULL) {
	    pkgPtr = Tcl_GetHashValue(hPtr);
	    if (pkgPtr->version != NULL) {
		goto require;
	    }
	}

	version = NULL;
	if (exact) {
	    version = TclGetString(objv[4]);
	    if (CheckVersionAndConvert(interp, version, NULL,
		    NULL) != TCL_OK) {
		return TCL_ERROR;
	    }
	} else {
	    if (CheckAllRequirements(interp, objc-3, objv+3) != TCL_OK) {
		return TCL_ERROR;
	    }
	    if ((objc > 3) && (CheckVersionAndConvert(interp,
		    TclGetString(objv[3]), NULL, NULL) == TCL_OK)) {
		version = TclGetString(objv[3]);
	    }
	}
	Tcl_PkgPresent(interp, name, version, exact);
	return TCL_ERROR;
	break;
    }
    case PKG_PROVIDE:
	if ((objc != 3) && (objc != 4)) {
	    Tcl_WrongNumArgs(interp, 2, objv, "package ?version?");
	    return TCL_ERROR;
	}
	argv2 = TclGetString(objv[2]);
	if (objc == 3) {
	    hPtr = Tcl_FindHashEntry(&iPtr->packageTable, argv2);
	    if (hPtr != NULL) {
		pkgPtr = Tcl_GetHashValue(hPtr);
		if (pkgPtr->version != NULL) {
		    Tcl_SetResult(interp, pkgPtr->version, TCL_VOLATILE);
		}
	    }
	    return TCL_OK;
	}
	argv3 = TclGetString(objv[3]);
	if (CheckVersionAndConvert(interp, argv3, NULL, NULL) != TCL_OK) {
	    return TCL_ERROR;
	}
	return Tcl_PkgProvide(interp, argv2, argv3);
    case PKG_REQUIRE:
    require:
	if (objc < 3) {
	requireSyntax:
	    Tcl_WrongNumArgs(interp, 2, objv,
		    "?-exact? package ?requirement...?");
	    return TCL_ERROR;
	}

	version = NULL;

	argv2 = TclGetString(objv[2]);
	if ((argv2[0] == '-') && (strcmp(argv2, "-exact") == 0)) {
	    Tcl_Obj *ov;
	    int res;

	    if (objc != 5) {
		goto requireSyntax;
	    }

	    version = TclGetString(objv[4]);
	    if (CheckVersionAndConvert(interp, version, NULL,
		    NULL) != TCL_OK) {
		return TCL_ERROR;
	    }

	    /*
	     * Create a new-style requirement for the exact version.
	     */

	    ov = Tcl_NewStringObj(version, -1);
	    Tcl_AppendStringsToObj(ov, "-", version, NULL);
	    version = NULL;
	    argv3 = TclGetString(objv[3]);

	    Tcl_IncrRefCount(ov);
	    res = Tcl_PkgRequireProc(interp, argv3, 1, &ov, NULL);
	    TclDecrRefCount(ov);
	    return res;
	} else {
	    if (CheckAllRequirements(interp, objc-3, objv+3) != TCL_OK) {
		return TCL_ERROR;
	    }

	    return Tcl_PkgRequireProc(interp, argv2, objc-3, objv+3, NULL);
	}
	break;
    case PKG_UNKNOWN: {
	int length;

	if (objc == 2) {
	    if (iPtr->packageUnknown != NULL) {
		Tcl_SetResult(interp, iPtr->packageUnknown, TCL_VOLATILE);
	    }
	} else if (objc == 3) {
	    if (iPtr->packageUnknown != NULL) {
		ckfree(iPtr->packageUnknown);
	    }
	    argv2 = Tcl_GetStringFromObj(objv[2], &length);
	    if (argv2[0] == 0) {
		iPtr->packageUnknown = NULL;
	    } else {
		DupBlock(iPtr->packageUnknown, argv2, (unsigned) length+1);
	    }
	} else {
	    Tcl_WrongNumArgs(interp, 2, objv, "?command?");
	    return TCL_ERROR;
	}
	break;
    }
    case PKG_PREFER: {
	static const char *pkgPreferOptions[] = {
	    "latest", "stable", NULL
	};

	/*
	 * See tclInt.h for the enum, just before Interp.
	 */

	if (objc > 3) {
	    Tcl_WrongNumArgs(interp, 2, objv, "?latest|stable?");
	    return TCL_ERROR;
	} else if (objc == 3) {
	    /*
	     * Seting the value.
	     */

	    int newPref;

	    if (Tcl_GetIndexFromObj(interp, objv[2], pkgPreferOptions,
		    "preference", 0, &newPref) != TCL_OK) {
		return TCL_ERROR;
	    }

	    if (newPref < iPtr->packagePrefer) {
		iPtr->packagePrefer = newPref;
	    }
	}

	/*
	 * Always return current value.
	 */

	Tcl_SetObjResult(interp,
		Tcl_NewStringObj(pkgPreferOptions[iPtr->packagePrefer], -1));
	break;
    }
    case PKG_VCOMPARE:
	if (objc != 4) {
	    Tcl_WrongNumArgs(interp, 2, objv, "version1 version2");
	    return TCL_ERROR;
	}
	argv3 = TclGetString(objv[3]);
	argv2 = TclGetString(objv[2]);
	if (CheckVersionAndConvert(interp, argv2, &iva, NULL) != TCL_OK ||
		CheckVersionAndConvert(interp, argv3, &ivb, NULL) != TCL_OK) {
	    if (iva != NULL) {
		ckfree(iva);
	    }

	    /*
	     * ivb cannot be set in this branch.
	     */

	    return TCL_ERROR;
	}

	/*
	 * Comparison is done on the internal representation.
	 */

	Tcl_SetObjResult(interp,
		Tcl_NewIntObj(CompareVersions(iva, ivb, NULL)));
	ckfree(iva);
	ckfree(ivb);
	break;
    case PKG_VERSIONS:
	if (objc != 3) {
	    Tcl_WrongNumArgs(interp, 2, objv, "package");
	    return TCL_ERROR;
	}
	argv2 = TclGetString(objv[2]);
	hPtr = Tcl_FindHashEntry(&iPtr->packageTable, argv2);
	if (hPtr != NULL) {
	    pkgPtr = Tcl_GetHashValue(hPtr);
	    for (availPtr = pkgPtr->availPtr; availPtr != NULL;
		    availPtr = availPtr->nextPtr) {
		Tcl_AppendElement(interp, availPtr->version);
	    }
	}
	break;
    case PKG_VSATISFIES: {
	char *argv2i = NULL;

	if (objc < 4) {
	    Tcl_WrongNumArgs(interp, 2, objv,
		    "version requirement requirement...");
	    return TCL_ERROR;
	}

	argv2 = TclGetString(objv[2]);
	if (CheckVersionAndConvert(interp, argv2, &argv2i, NULL) != TCL_OK) {
	    return TCL_ERROR;
	} else if (CheckAllRequirements(interp, objc-3, objv+3) != TCL_OK) {
	    ckfree(argv2i);
	    return TCL_ERROR;
	}

	satisfies = SomeRequirementSatisfied(argv2i, objc-3, objv+3);
	ckfree(argv2i);

	Tcl_SetObjResult(interp, Tcl_NewBooleanObj(satisfies));
	break;
    }
    default:
	Tcl_Panic("Tcl_PackageObjCmd: bad option index to pkgOptions");
    }
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * FindPackage --
 *
 *	This function finds the Package record for a particular package in a
 *	particular interpreter, creating a record if one doesn't already
 *	exist.
 *
 * Results:
 *	The return value is a pointer to the Package record for the package.
 *
 * Side effects:
 *	A new Package record may be created.
 *
 *----------------------------------------------------------------------
 */

static Package *
FindPackage(
    Tcl_Interp *interp,		/* Interpreter to use for package lookup. */
    const char *name)		/* Name of package to fine. */
{
    Interp *iPtr = (Interp *) interp;
    Tcl_HashEntry *hPtr;
    int isNew;
    Package *pkgPtr;

    hPtr = Tcl_CreateHashEntry(&iPtr->packageTable, name, &isNew);
    if (isNew) {
	pkgPtr = (Package *) ckalloc(sizeof(Package));
	pkgPtr->version = NULL;
	pkgPtr->availPtr = NULL;
	pkgPtr->clientData = NULL;
	Tcl_SetHashValue(hPtr, pkgPtr);
    } else {
	pkgPtr = Tcl_GetHashValue(hPtr);
    }
    return pkgPtr;
}

/*
 *----------------------------------------------------------------------
 *
 * TclFreePackageInfo --
 *
 *	This function is called during interpreter deletion to free all of the
 *	package-related information for the interpreter.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Memory is freed.
 *
 *----------------------------------------------------------------------
 */

void
TclFreePackageInfo(
    Interp *iPtr)		/* Interpereter that is being deleted. */
{
    Package *pkgPtr;
    Tcl_HashSearch search;
    Tcl_HashEntry *hPtr;
    PkgAvail *availPtr;

    for (hPtr = Tcl_FirstHashEntry(&iPtr->packageTable, &search);
	    hPtr != NULL; hPtr = Tcl_NextHashEntry(&search)) {
	pkgPtr = Tcl_GetHashValue(hPtr);
	if (pkgPtr->version != NULL) {
	    ckfree(pkgPtr->version);
	}
	while (pkgPtr->availPtr != NULL) {
	    availPtr = pkgPtr->availPtr;
	    pkgPtr->availPtr = availPtr->nextPtr;
	    Tcl_EventuallyFree((ClientData)availPtr->version, TCL_DYNAMIC);
	    Tcl_EventuallyFree((ClientData)availPtr->script, TCL_DYNAMIC);
	    ckfree((char *) availPtr);
	}
	ckfree((char *) pkgPtr);
    }
    Tcl_DeleteHashTable(&iPtr->packageTable);
    if (iPtr->packageUnknown != NULL) {
	ckfree(iPtr->packageUnknown);
    }
}

/*
 *----------------------------------------------------------------------
 *
 * CheckVersionAndConvert --
 *
 *	This function checks to see whether a version number has valid syntax.
 *	It also generates a semi-internal representation (string rep of a list
 *	of numbers).
 *
 * Results:
 *	If string is a properly formed version number the TCL_OK is returned.
 *	Otherwise TCL_ERROR is returned and an error message is left in the
 *	interp's result.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

static int
CheckVersionAndConvert(
    Tcl_Interp *interp,		/* Used for error reporting. */
    const char *string,		/* Supposedly a version number, which is
				 * groups of decimal digits separated by
				 * dots. */
    char **internal,		/* Internal normalized representation */
    int *stable)		/* Flag: Version is (un)stable. */
{
    const char *p = string;
    char prevChar;
    int hasunstable = 0;
    /*
     * 4* assuming that each char is a separator (a,b become ' -x ').
     * 4+ to have spce for an additional -2 at the end
     */
    char *ibuf = ckalloc(4 + 4*strlen(string));
    char *ip = ibuf;

    /*
     * Basic rules
     * (1) First character has to be a digit.
     * (2) All other characters have to be a digit or '.'
     * (3) Two '.'s may not follow each other.
     *
     * TIP 268, Modified rules
     * (1) s.a.
     * (2) All other characters have to be a digit, 'a', 'b', or '.'
     * (3) s.a.
     * (4) Only one of 'a' or 'b' may occur.
     * (5) Neither 'a', nor 'b' may occur before or after a '.'
     */

    if (!isdigit(UCHAR(*p))) {				/* INTL: digit */
	goto error;
    }

    *ip++ = *p;

    for (prevChar = *p, p++; *p != 0; p++) {
	if (!isdigit(UCHAR(*p)) &&			/* INTL: digit */
		((*p!='.' && *p!='a' && *p!='b') ||
		((hasunstable && (*p=='a' || *p=='b')) ||
		((prevChar=='a' || prevChar=='b' || prevChar=='.')
			&& (*p=='.')) ||
		((*p=='a' || *p=='b' || *p=='.') && prevChar=='.')))) {
	    goto error;
	}

	if (*p == 'a' || *p == 'b') {
	    hasunstable = 1;
	}

	/*
	 * Translation to the internal rep. Regular version chars are copied
	 * as is. The separators are translated to numerics. The new separator
	 * for all parts is space.
	 */

	if (*p == '.') {
	    *ip++ = ' ';
	    *ip++ = '0';
	    *ip++ = ' ';
	} else if (*p == 'a') {
	    *ip++ = ' ';
	    *ip++ = '-';
	    *ip++ = '2';
	    *ip++ = ' ';
	} else if (*p == 'b') {
	    *ip++ = ' ';
	    *ip++ = '-';
	    *ip++ = '1';
	    *ip++ = ' ';
	} else {
	    *ip++ = *p;
	}

	prevChar = *p;
    }
    if (prevChar!='.' && prevChar!='a' && prevChar!='b') {
	*ip = '\0';
	if (internal != NULL) {
	    *internal = ibuf;
	} else {
	    ckfree(ibuf);
	}
	if (stable != NULL) {
	    *stable = !hasunstable;
	}
	return TCL_OK;
    }

  error:
    ckfree(ibuf);
    Tcl_AppendResult(interp, "expected version number but got \"", string,
	    "\"", NULL);
    return TCL_ERROR;
}

/*
 *----------------------------------------------------------------------
 *
 * CompareVersions --
 *
 *	This function compares two version numbers (in internal rep).
 *
 * Results:
 *	The return value is -1 if v1 is less than v2, 0 if the two version
 *	numbers are the same, and 1 if v1 is greater than v2. If *satPtr is
 *	non-NULL, the word it points to is filled in with 1 if v2 >= v1 and
 *	both numbers have the same major number or 0 otherwise.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

static int
CompareVersions(
    char *v1, char *v2,		/* Versions strings, of form 2.1.3 (any number
				 * of version numbers). */
    int *isMajorPtr)		/* If non-null, the word pointed to is filled
				 * in with a 0/1 value. 1 means that the
				 * difference occured in the first element. */
{
    int thisIsMajor, res, flip;
    char *s1, *e1, *s2, *e2, o1, o2;

    /*
     * Each iteration of the following loop processes one number from each
     * string, terminated by a " " (space). If those numbers don't match then
     * the comparison is over; otherwise, we loop back for the next number.
     *
     * TIP 268.
     * This is identical the function 'ComparePkgVersion', but using the new
     * space separator as used by the internal rep of version numbers. The
     * special separators 'a' and 'b' have already been dealt with in
     * 'CheckVersionAndConvert', they were translated into numbers as well.
     * This keeps the comparison sane. Otherwise we would have to compare
     * numerics, the separators, and also deal with the special case of
     * end-of-string compared to separators. The semi-list rep we get here is
     * much easier to handle, as it is still regular.
     *
     * Rewritten to not compute a numeric value for the extracted version
     * number, but do string comparison. Skip any leading zeros for that to
     * work. This change breaks through the 32bit-limit on version numbers.
     */

    thisIsMajor = 1;
    s1 = v1;
    s2 = v2;

    while (1) {
	/*
	 * Parse one decimal number from the front of each string. Skip
	 * leading zeros. Terminate found number for upcoming string-wise
	 * comparison, if needed.
	 */

	while ((*s1 != 0) && (*s1 == '0')) {
	    s1++;
	}
	while ((*s2 != 0) && (*s2 == '0')) {
	    s2++;
	}

	/*
	 * s1, s2 now point to the beginnings of the numbers to compare. Test
	 * for their signs first, as shortcut to the result (different signs),
	 * or determines if result has to be flipped (both negative). If there
	 * is no shortcut we have to insert terminators later to limit the
	 * strcmp.
	 */

	if ((*s1 == '-') && (*s2 != '-')) {
	    /* s1 < 0, s2 >= 0 => s1 < s2 */
	    res = -1;
	    break;
	}
	if ((*s1 != '-') && (*s2 == '-')) {
	    /* s1 >= 0, s2 < 0 => s1 > s2 */
	    res = 1;
	    break;
	}

	if ((*s1 == '-') && (*s2 == '-')) {
	    /* a < b => -a > -b, etc. */
	    s1++;
	    s2++;
	    flip = 1;
	} else {
	    flip = 0;
	}

	/*
	 * The string comparison is needed, so now we determine where the
	 * numbers end.
	 */

	e1 = s1;
	while ((*e1 != 0) && (*e1 != ' ')) {
	    e1++;
	}
	e2 = s2;
	while ((*e2 != 0) && (*e2 != ' ')) {
	    e2++;
	}

	/*
	 * s1 .. e1 and s2 .. e2 now bracket the numbers to compare. Insert
	 * terminators, compare, and restore actual contents. First however
	 * another shortcut. Compare lengths. Shorter string is smaller
	 * number! Thus we strcmp only strings of identical length.
	 */

	if ((e1-s1) < (e2-s2)) {
	    res = -1;
	} else if ((e2-s2) < (e1-s1)) {
	    res = 1;
	} else {
	    o1 = *e1;
	    *e1 = '\0';
	    o2 = *e2;
	    *e2 = '\0';

	    res = strcmp(s1, s2);
	    res = (res < 0) ? -1 : (res ? 1 : 0);

	    *e1 = o1;
	    *e2 = o2;
	}

	/*
	 * Stop comparing segments when a difference has been found. Here we
	 * may have to flip the result to account for signs.
	 */

	if (res != 0) {
	    if (flip) {
		res = -res;
	    }
	    break;
	}

	/*
	 * Go on to the next version number if the current numbers match.
	 * However stop processing if the end of both numbers has been
	 * reached.
	 */

	s1 = e1;
	s2 = e2;

	if (*s1 != 0) {
	    s1++;
	} else if (*s2 == 0) {
	    /*
	     * s1, s2 both at the end => identical
	     */

	    res = 0;
	    break;
	}
	if (*s2 != 0) {
	    s2++;
	}
	thisIsMajor = 0;
    }

    if (isMajorPtr != NULL) {
	*isMajorPtr = thisIsMajor;
    }

    return res;
}

/*
 *----------------------------------------------------------------------
 *
 * CheckAllRequirements --
 *
 *	This function checks to see whether all requirements in a set have
 *	valid syntax.
 *
 * Results:
 *	TCL_OK is returned if all requirements are valid. Otherwise TCL_ERROR
 *	is returned and an error message is left in the interp's result.
 *
 * Side effects:
 *	May modify the interpreter result.
 *
 *----------------------------------------------------------------------
 */

static int
CheckAllRequirements(
    Tcl_Interp *interp,
    int reqc,			/* Requirements to check. */
    Tcl_Obj *const reqv[])
{
    int i;

    for (i = 0; i < reqc; i++) {
	if ((CheckRequirement(interp, TclGetString(reqv[i])) != TCL_OK)) {
	    return TCL_ERROR;
	}
    }
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * CheckRequirement --
 *
 *	This function checks to see whether a requirement has valid syntax.
 *
 * Results:
 *	If string is a properly formed requirement then TCL_OK is returned.
 *	Otherwise TCL_ERROR is returned and an error message is left in the
 *	interp's result.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

static int
CheckRequirement(
    Tcl_Interp *interp,		/* Used for error reporting. */
    const char *string)		/* Supposedly a requirement. */
{
    /*
     * Syntax of requirement = version
     *			     = version-version
     *			     = version-
     */

    char *dash = NULL, *buf;

    dash = strchr(string, '-');
    if (dash == NULL) {
	/*
	 * No dash found, has to be a simple version.
	 */

	return CheckVersionAndConvert(interp, string, NULL, NULL);
    }

    if (strchr(dash+1, '-') != NULL) {
	/*
	 * More dashes found after the first. This is wrong.
	 */

	Tcl_AppendResult(interp, "expected versionMin-versionMax but got \"",
		string, "\"", NULL);
	return TCL_ERROR;
    }

    /*
     * Exactly one dash is present. Copy the string, split at the location of
     * dash and check that both parts are versions. Note that the max part can
     * be empty. Also note that the string allocated with strdup() must be
     * freed with free() and not ckfree().
     */

    DupString(buf, string);
    dash = buf + (dash - string);
    *dash = '\0';		/* buf now <=> min part */
    dash++;			/* dash now <=> max part */

    if ((CheckVersionAndConvert(interp, buf, NULL, NULL) != TCL_OK) ||
	    ((*dash != '\0') &&
	    (CheckVersionAndConvert(interp, dash, NULL, NULL) != TCL_OK))) {
	ckfree(buf);
	return TCL_ERROR;
    }

    ckfree(buf);
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * AddRequirementsToResult --
 *
 *	This function accumulates requirements in the interpreter result.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	The interpreter result is extended.
 *
 *----------------------------------------------------------------------
 */

static void
AddRequirementsToResult(
    Tcl_Interp *interp,
    int reqc,			/* Requirements constraining the desired
				 * version. */
    Tcl_Obj *const reqv[])	/* 0 means to use the latest version
				 * available. */
{
    if (reqc > 0) {
	int i;

	for (i = 0; i < reqc; i++) {
	    int length;
	    char *v = Tcl_GetStringFromObj(reqv[i], &length);

	    if ((length & 0x1) && (v[length/2] == '-')
		    && (strncmp(v, v+((length+1)/2), length/2) == 0)) {
		Tcl_AppendResult(interp, " exactly ", v+((length+1)/2), NULL);
	    } else {
		Tcl_AppendResult(interp, " ", v, NULL);
	    }
	}
    }
}

/*
 *----------------------------------------------------------------------
 *
 * AddRequirementsToDString --
 *
 *	This function accumulates requirements in a DString.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	The DString argument is extended.
 *
 *----------------------------------------------------------------------
 */

static void
AddRequirementsToDString(
    Tcl_DString *dsPtr,
    int reqc,			/* Requirements constraining the desired
				 * version. */
    Tcl_Obj *const reqv[])	/* 0 means to use the latest version
				 * available. */
{
    if (reqc > 0) {
	int i;

	for (i = 0; i < reqc; i++) {
	    Tcl_DStringAppend(dsPtr, " ", 1);
	    Tcl_DStringAppend(dsPtr, TclGetString(reqv[i]), -1);
	}
    } else {
	Tcl_DStringAppend(dsPtr, " 0-", -1);
    }
}

/*
 *----------------------------------------------------------------------
 *
 * SomeRequirementSatisfied --
 *
 *	This function checks to see whether a version satisfies at least one
 *	of a set of requirements.
 *
 * Results:
 *	If the requirements are satisfied 1 is returned. Otherwise 0 is
 *	returned. The function assumes that all pieces have valid syntax. And
 *	is allowed to make that assumption.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

static int
SomeRequirementSatisfied(
    char *availVersionI,	/* Candidate version to check against the
				 * requirements. */
    int reqc,			/* Requirements constraining the desired
				 * version. */
    Tcl_Obj *const reqv[])	/* 0 means to use the latest version
				 * available. */
{
    int i;

    for (i = 0; i < reqc; i++) {
	if (RequirementSatisfied(availVersionI, TclGetString(reqv[i]))) {
	    return 1;
	}
    }
    return 0;
}

/*
 *----------------------------------------------------------------------
 *
 * RequirementSatisfied --
 *
 *	This function checks to see whether a version satisfies a requirement.
 *
 * Results:
 *	If the requirement is satisfied 1 is returned. Otherwise 0 is
 *	returned. The function assumes that all pieces have valid syntax, and
 *	is allowed to make that assumption.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

static int
RequirementSatisfied(
    char *havei,		/* Version string, of candidate package we
				 * have. */
    const char *req)		/* Requirement string the candidate has to
				 * satisfy. */
{
    /*
     * The have candidate is already in internal rep.
     */

    int satisfied, res;
    char *dash = NULL, *buf, *min, *max;

    dash = strchr(req, '-');
    if (dash == NULL) {
	/*
	 * No dash found, is a simple version, fallback to regular check. The
	 * 'CheckVersionAndConvert' cannot fail. We pad the requirement with
	 * 'a0', i.e '-2' before doing the comparison to properly accept
	 * unstables as well.
	 */

	char *reqi = NULL;
	int thisIsMajor;

	CheckVersionAndConvert(NULL, req, &reqi, NULL);
	strcat(reqi, " -2");
	res = CompareVersions(havei, reqi, &thisIsMajor);
	satisfied = (res == 0) || ((res == 1) && !thisIsMajor);
	ckfree(reqi);
	return satisfied;
    }

    /*
     * Exactly one dash is present (Assumption of valid syntax). Copy the req,
     * split at the location of dash and check that both parts are versions.
     * Note that the max part can be empty.
     */

    DupString(buf, req);
    dash = buf + (dash - req);
    *dash = '\0';		/* buf now <=> min part */
    dash++;			/* dash now <=> max part */

    if (*dash == '\0') {
	/*
	 * We have a min, but no max. For the comparison we generate the
	 * internal rep, padded with 'a0' i.e. '-2'.
	 */

	CheckVersionAndConvert(NULL, buf, &min, NULL);
	strcat(min, " -2");
	satisfied = (CompareVersions(havei, min, NULL) >= 0);
	ckfree(min);
	ckfree(buf);
	return satisfied;
    }

    /*
     * We have both min and max, and generate their internal reps. When
     * identical we compare as is, otherwise we pad with 'a0' to ove the range
     * a bit.
     */

    CheckVersionAndConvert(NULL, buf, &min, NULL);
    CheckVersionAndConvert(NULL, dash, &max, NULL);

    if (CompareVersions(min, max, NULL) == 0) {
	satisfied = (CompareVersions(min, havei, NULL) == 0);
    } else {
	strcat(min, " -2");
	strcat(max, " -2");
	satisfied = ((CompareVersions(min, havei, NULL) <= 0) &&
		(CompareVersions(havei, max, NULL) < 0));
    }

    ckfree(min);
    ckfree(max);
    ckfree(buf);
    return satisfied;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_PkgInitStubsCheck --
 *
 *	This is a replacement routine for Tcl_InitStubs() that is called
 *	from code where -DUSE_TCL_STUBS has not been enabled.
 *
 * Results:
 *	Returns the version of a conforming stubs table, or NULL, if
 *	the table version doesn't satisfy the requested requirements,
 *	according to historical practice.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

const char *
Tcl_PkgInitStubsCheck(
    Tcl_Interp *interp,
    const char * version,
    int exact)
{
    const char *actualVersion = Tcl_PkgPresent(interp, "Tcl", version, 0);

    if (exact && actualVersion) {
	const char *p = version;
	int count = 0;

	while (*p) {
	    count += !isdigit(UCHAR(*p++));
	}
	if (count == 1) {
	    if (0 != strncmp(version, actualVersion, strlen(version))) {
		/* Construct error message */
		Tcl_PkgPresent(interp, "Tcl", version, 1);
		return NULL;
	    }
	} else {
	    return Tcl_PkgPresent(interp, "Tcl", version, 1);
	}
    }
    return actualVersion;
}
/*
 * Local Variables:
 * mode: c
 * c-basic-offset: 4
 * fill-column: 78
 * End:
 */