Merge p3yk branch with the trunk up to revision 45595. This breaks a fair

number of tests, all because of the codecs/_multibytecodecs issue described
here (it's not a Py3K issue, just something Py3K discovers):
http://mail.python.org/pipermail/python-dev/2006-April/064051.html

Hye-Shik Chang promised to look for a fix, so no need to fix it here. The
tests that are expected to break are:

test_codecencodings_cn
test_codecencodings_hk
test_codecencodings_jp
test_codecencodings_kr
test_codecencodings_tw
test_codecs
test_multibytecodec

This merge fixes an actual test failure (test_weakref) in this branch,
though, so I believe merging is the right thing to do anyway.

1 files changed, 348 insertions, 0 deletions

diff --git a/Lib/email/generator.py b/Lib/email/generator.py
new file mode 100644
index 0000000..6e7a515
--- /dev/null
+++ b/Lib/email/generator.py
@@ -0,0 +1,348 @@
+# Copyright (C) 2001-2006 Python Software Foundation
+# Author: Barry Warsaw
+# Contact: email-sig@python.org
+
+"""Classes to generate plain text from a message object tree."""
+
+__all__ = ['Generator', 'DecodedGenerator']
+
+import re
+import sys
+import time
+import random
+import warnings
+
+from cStringIO import StringIO
+from email.header import Header
+
+UNDERSCORE = '_'
+NL = '\n'
+
+fcre = re.compile(r'^From ', re.MULTILINE)
+
+def _is8bitstring(s):
+    if isinstance(s, str):
+        try:
+            unicode(s, 'us-ascii')
+        except UnicodeError:
+            return True
+    return False
+
+
+
+class Generator:
+    """Generates output from a Message object tree.
+
+    This basic generator writes the message to the given file object as plain
+    text.
+    """
+    #
+    # Public interface
+    #
+
+    def __init__(self, outfp, mangle_from_=True, maxheaderlen=78):
+        """Create the generator for message flattening.
+
+        outfp is the output file-like object for writing the message to.  It
+        must have a write() method.
+
+        Optional mangle_from_ is a flag that, when True (the default), escapes
+        From_ lines in the body of the message by putting a `>' in front of
+        them.
+
+        Optional maxheaderlen specifies the longest length for a non-continued
+        header.  When a header line is longer (in characters, with tabs
+        expanded to 8 spaces) than maxheaderlen, the header will split as
+        defined in the Header class.  Set maxheaderlen to zero to disable
+        header wrapping.  The default is 78, as recommended (but not required)
+        by RFC 2822.
+        """
+        self._fp = outfp
+        self._mangle_from_ = mangle_from_
+        self._maxheaderlen = maxheaderlen
+
+    def write(self, s):
+        # Just delegate to the file object
+        self._fp.write(s)
+
+    def flatten(self, msg, unixfrom=False):
+        """Print the message object tree rooted at msg to the output file
+        specified when the Generator instance was created.
+
+        unixfrom is a flag that forces the printing of a Unix From_ delimiter
+        before the first object in the message tree.  If the original message
+        has no From_ delimiter, a `standard' one is crafted.  By default, this
+        is False to inhibit the printing of any From_ delimiter.
+
+        Note that for subobjects, no From_ line is printed.
+        """
+        if unixfrom:
+            ufrom = msg.get_unixfrom()
+            if not ufrom:
+                ufrom = 'From nobody ' + time.ctime(time.time())
+            print >> self._fp, ufrom
+        self._write(msg)
+
+    def clone(self, fp):
+        """Clone this generator with the exact same options."""
+        return self.__class__(fp, self._mangle_from_, self._maxheaderlen)
+
+    #
+    # Protected interface - undocumented ;/
+    #
+
+    def _write(self, msg):
+        # We can't write the headers yet because of the following scenario:
+        # say a multipart message includes the boundary string somewhere in
+        # its body.  We'd have to calculate the new boundary /before/ we write
+        # the headers so that we can write the correct Content-Type:
+        # parameter.
+        #
+        # The way we do this, so as to make the _handle_*() methods simpler,
+        # is to cache any subpart writes into a StringIO.  The we write the
+        # headers and the StringIO contents.  That way, subpart handlers can
+        # Do The Right Thing, and can still modify the Content-Type: header if
+        # necessary.
+        oldfp = self._fp
+        try:
+            self._fp = sfp = StringIO()
+            self._dispatch(msg)
+        finally:
+            self._fp = oldfp
+        # Write the headers.  First we see if the message object wants to
+        # handle that itself.  If not, we'll do it generically.
+        meth = getattr(msg, '_write_headers', None)
+        if meth is None:
+            self._write_headers(msg)
+        else:
+            meth(self)
+        self._fp.write(sfp.getvalue())
+
+    def _dispatch(self, msg):
+        # Get the Content-Type: for the message, then try to dispatch to
+        # self._handle_<maintype>_<subtype>().  If there's no handler for the
+        # full MIME type, then dispatch to self._handle_<maintype>().  If
+        # that's missing too, then dispatch to self._writeBody().
+        main = msg.get_content_maintype()
+        sub = msg.get_content_subtype()
+        specific = UNDERSCORE.join((main, sub)).replace('-', '_')
+        meth = getattr(self, '_handle_' + specific, None)
+        if meth is None:
+            generic = main.replace('-', '_')
+            meth = getattr(self, '_handle_' + generic, None)
+            if meth is None:
+                meth = self._writeBody
+        meth(msg)
+
+    #
+    # Default handlers
+    #
+
+    def _write_headers(self, msg):
+        for h, v in msg.items():
+            print >> self._fp, '%s:' % h,
+            if self._maxheaderlen == 0:
+                # Explicit no-wrapping
+                print >> self._fp, v
+            elif isinstance(v, Header):
+                # Header instances know what to do
+                print >> self._fp, v.encode()
+            elif _is8bitstring(v):
+                # If we have raw 8bit data in a byte string, we have no idea
+                # what the encoding is.  There is no safe way to split this
+                # string.  If it's ascii-subset, then we could do a normal
+                # ascii split, but if it's multibyte then we could break the
+                # string.  There's no way to know so the least harm seems to
+                # be to not split the string and risk it being too long.
+                print >> self._fp, v
+            else:
+                # Header's got lots of smarts, so use it.
+                print >> self._fp, Header(
+                    v, maxlinelen=self._maxheaderlen,
+                    header_name=h, continuation_ws='\t').encode()
+        # A blank line always separates headers from body
+        print >> self._fp
+
+    #
+    # Handlers for writing types and subtypes
+    #
+
+    def _handle_text(self, msg):
+        payload = msg.get_payload()
+        if payload is None:
+            return
+        if not isinstance(payload, basestring):
+            raise TypeError('string payload expected: %s' % type(payload))
+        if self._mangle_from_:
+            payload = fcre.sub('>From ', payload)
+        self._fp.write(payload)
+
+    # Default body handler
+    _writeBody = _handle_text
+
+    def _handle_multipart(self, msg):
+        # The trick here is to write out each part separately, merge them all
+        # together, and then make sure that the boundary we've chosen isn't
+        # present in the payload.
+        msgtexts = []
+        subparts = msg.get_payload()
+        if subparts is None:
+            subparts = []
+        elif isinstance(subparts, basestring):
+            # e.g. a non-strict parse of a message with no starting boundary.
+            self._fp.write(subparts)
+            return
+        elif not isinstance(subparts, list):
+            # Scalar payload
+            subparts = [subparts]
+        for part in subparts:
+            s = StringIO()
+            g = self.clone(s)
+            g.flatten(part, unixfrom=False)
+            msgtexts.append(s.getvalue())
+        # Now make sure the boundary we've selected doesn't appear in any of
+        # the message texts.
+        alltext = NL.join(msgtexts)
+        # BAW: What about boundaries that are wrapped in double-quotes?
+        boundary = msg.get_boundary(failobj=_make_boundary(alltext))
+        # If we had to calculate a new boundary because the body text
+        # contained that string, set the new boundary.  We don't do it
+        # unconditionally because, while set_boundary() preserves order, it
+        # doesn't preserve newlines/continuations in headers.  This is no big
+        # deal in practice, but turns out to be inconvenient for the unittest
+        # suite.
+        if msg.get_boundary() <> boundary:
+            msg.set_boundary(boundary)
+        # If there's a preamble, write it out, with a trailing CRLF
+        if msg.preamble is not None:
+            print >> self._fp, msg.preamble
+        # dash-boundary transport-padding CRLF
+        print >> self._fp, '--' + boundary
+        # body-part
+        if msgtexts:
+            self._fp.write(msgtexts.pop(0))
+        # *encapsulation
+        # --> delimiter transport-padding
+        # --> CRLF body-part
+        for body_part in msgtexts:
+            # delimiter transport-padding CRLF
+            print >> self._fp, '\n--' + boundary
+            # body-part
+            self._fp.write(body_part)
+        # close-delimiter transport-padding
+        self._fp.write('\n--' + boundary + '--')
+        if msg.epilogue is not None:
+            print >> self._fp
+            self._fp.write(msg.epilogue)
+
+    def _handle_message_delivery_status(self, msg):
+        # We can't just write the headers directly to self's file object
+        # because this will leave an extra newline between the last header
+        # block and the boundary.  Sigh.
+        blocks = []
+        for part in msg.get_payload():
+            s = StringIO()
+            g = self.clone(s)
+            g.flatten(part, unixfrom=False)
+            text = s.getvalue()
+            lines = text.split('\n')
+            # Strip off the unnecessary trailing empty line
+            if lines and lines[-1] == '':
+                blocks.append(NL.join(lines[:-1]))
+            else:
+                blocks.append(text)
+        # Now join all the blocks with an empty line.  This has the lovely
+        # effect of separating each block with an empty line, but not adding
+        # an extra one after the last one.
+        self._fp.write(NL.join(blocks))
+
+    def _handle_message(self, msg):
+        s = StringIO()
+        g = self.clone(s)
+        # The payload of a message/rfc822 part should be a multipart sequence
+        # of length 1.  The zeroth element of the list should be the Message
+        # object for the subpart.  Extract that object, stringify it, and
+        # write it out.
+        g.flatten(msg.get_payload(0), unixfrom=False)
+        self._fp.write(s.getvalue())
+
+
+
+_FMT = '[Non-text (%(type)s) part of message omitted, filename %(filename)s]'
+
+class DecodedGenerator(Generator):
+    """Generator a text representation of a message.
+
+    Like the Generator base class, except that non-text parts are substituted
+    with a format string representing the part.
+    """
+    def __init__(self, outfp, mangle_from_=True, maxheaderlen=78, fmt=None):
+        """Like Generator.__init__() except that an additional optional
+        argument is allowed.
+
+        Walks through all subparts of a message.  If the subpart is of main
+        type `text', then it prints the decoded payload of the subpart.
+
+        Otherwise, fmt is a format string that is used instead of the message
+        payload.  fmt is expanded with the following keywords (in
+        %(keyword)s format):
+
+        type       : Full MIME type of the non-text part
+        maintype   : Main MIME type of the non-text part
+        subtype    : Sub-MIME type of the non-text part
+        filename   : Filename of the non-text part
+        description: Description associated with the non-text part
+        encoding   : Content transfer encoding of the non-text part
+
+        The default value for fmt is None, meaning
+
+        [Non-text (%(type)s) part of message omitted, filename %(filename)s]
+        """
+        Generator.__init__(self, outfp, mangle_from_, maxheaderlen)
+        if fmt is None:
+            self._fmt = _FMT
+        else:
+            self._fmt = fmt
+
+    def _dispatch(self, msg):
+        for part in msg.walk():
+            maintype = part.get_content_maintype()
+            if maintype == 'text':
+                print >> self, part.get_payload(decode=True)
+            elif maintype == 'multipart':
+                # Just skip this
+                pass
+            else:
+                print >> self, self._fmt % {
+                    'type'       : part.get_content_type(),
+                    'maintype'   : part.get_content_maintype(),
+                    'subtype'    : part.get_content_subtype(),
+                    'filename'   : part.get_filename('[no filename]'),
+                    'description': part.get('Content-Description',
+                                            '[no description]'),
+                    'encoding'   : part.get('Content-Transfer-Encoding',
+                                            '[no encoding]'),
+                    }
+
+
+
+# Helper
+_width = len(repr(sys.maxint-1))
+_fmt = '%%0%dd' % _width
+
+def _make_boundary(text=None):
+    # Craft a random boundary.  If text is given, ensure that the chosen
+    # boundary doesn't appear in the text.
+    token = random.randrange(sys.maxint)
+    boundary = ('=' * 15) + (_fmt % token) + '=='
+    if text is None:
+        return boundary
+    b = boundary
+    counter = 0
+    while True:
+        cre = re.compile('^--' + re.escape(b) + '(--)?$', re.MULTILINE)
+        if not cre.search(text):
+            break
+        b = boundary + '.' + str(counter)
+        counter += 1
+    return b