Issue #22286: The "backslashreplace" error handlers now works with

decoding and translating.

5 files changed, 25 insertions, 16 deletions

diff --git a/Doc/howto/unicode.rst b/Doc/howto/unicode.rst
index 5ea311e..ee31a9c 100644
--- a/Doc/howto/unicode.rst
+++ b/Doc/howto/unicode.rst
@@ -280,8 +280,9 @@ and optionally an *errors* argument.
 The *errors* argument specifies the response when the input string can't be
 converted according to the encoding's rules.  Legal values for this argument are
 ``'strict'`` (raise a :exc:`UnicodeDecodeError` exception), ``'replace'`` (use
-``U+FFFD``, ``REPLACEMENT CHARACTER``), or ``'ignore'`` (just leave the
-character out of the Unicode result).
+``U+FFFD``, ``REPLACEMENT CHARACTER``), ``'ignore'`` (just leave the
+character out of the Unicode result), or ``'backslashreplace'`` (inserts a
+``\xNN`` escape sequence).
 The following examples show the differences::
 
     >>> b'\x80abc'.decode("utf-8", "strict")  #doctest: +NORMALIZE_WHITESPACE
@@ -291,6 +292,8 @@ The following examples show the differences::
       invalid start byte
     >>> b'\x80abc'.decode("utf-8", "replace")
     '\ufffdabc'
+    >>> b'\x80abc'.decode("utf-8", "backslashreplace")
+    '\\x80abc'
     >>> b'\x80abc'.decode("utf-8", "ignore")
     'abc'
 
diff --git a/Doc/library/codecs.rst b/Doc/library/codecs.rst
index 3510f69..048f0e9 100644
--- a/Doc/library/codecs.rst
+++ b/Doc/library/codecs.rst
@@ -314,8 +314,8 @@ The following error handlers are only applicable to
 |                         | reference (only for encoding).  Implemented   |
 |                         | in :func:`xmlcharrefreplace_errors`.          |
 +-------------------------+-----------------------------------------------+
-| ``'backslashreplace'``  | Replace with backslashed escape sequences     |
-|                         | (only for encoding).  Implemented in          |
+| ``'backslashreplace'``  | Replace with backslashed escape sequences.    |
+|                         | Implemented in                                |
 |                         | :func:`backslashreplace_errors`.              |
 +-------------------------+-----------------------------------------------+
 | ``'namereplace'``       | Replace with ``\N{...}`` escape sequences     |
@@ -350,6 +350,10 @@ In addition, the following error handler is specific to the given codecs:
 .. versionadded:: 3.5
    The ``'namereplace'`` error handler.
 
+.. versionchanged:: 3.5
+   The ``'backslashreplace'`` error handlers now works with decoding and
+   translating.
+
 The set of allowed values can be extended by registering a new named error
 handler:
 
@@ -417,9 +421,9 @@ functions:
 
 .. function:: backslashreplace_errors(exception)
 
-   Implements the ``'backslashreplace'`` error handling (for encoding with
-   :term:`text encodings <text encoding>` only): the
-   unencodable character is replaced by a backslashed escape sequence.
+   Implements the ``'backslashreplace'`` error handling (for
+   :term:`text encodings <text encoding>` only): malformed data is
+   replaced by a backslashed escape sequence.
 
 .. function:: namereplace_errors(exception)
 
diff --git a/Doc/library/functions.rst b/Doc/library/functions.rst
index c6b66b5..eb28513 100644
--- a/Doc/library/functions.rst
+++ b/Doc/library/functions.rst
@@ -973,9 +973,8 @@ are always available.  They are listed here in alphabetical order.
      Characters not supported by the encoding are replaced with the
      appropriate XML character reference ``&#nnn;``.
 
-   * ``'backslashreplace'`` (also only supported when writing)
-     replaces unsupported characters with Python's backslashed escape
-     sequences.
+   * ``'backslashreplace'`` replaces malformed data by Python's backslashed
+     escape sequences.
 
    * ``'namereplace'`` (also only supported when writing)
      replaces unsupported characters with ``\N{...}`` escape sequences.
diff --git a/Doc/library/io.rst b/Doc/library/io.rst
index c77db90..b0b1af3 100644
--- a/Doc/library/io.rst
+++ b/Doc/library/io.rst
@@ -825,11 +825,12 @@ Text I/O
    exception if there is an encoding error (the default of ``None`` has the same
    effect), or pass ``'ignore'`` to ignore errors.  (Note that ignoring encoding
    errors can lead to data loss.)  ``'replace'`` causes a replacement marker
-   (such as ``'?'``) to be inserted where there is malformed data.  When
-   writing, ``'xmlcharrefreplace'`` (replace with the appropriate XML character
-   reference), ``'backslashreplace'`` (replace with backslashed escape
-   sequences) or ``'namereplace'`` (replace with ``\N{...}`` escape sequences)
-   can be used.  Any other error handling name that has been registered with
+   (such as ``'?'``) to be inserted where there is malformed data.
+   ``'backslashreplace'`` causes malformed data to be replaced by a
+   backslashed escape sequence.  When writing, ``'xmlcharrefreplace'``
+   (replace with the appropriate XML character reference)  or ``'namereplace'``
+   (replace with ``\N{...}`` escape sequences) can be used.  Any other error
+   handling name that has been registered with
    :func:`codecs.register_error` is also valid.
 
    .. index::
diff --git a/Doc/whatsnew/3.5.rst b/Doc/whatsnew/3.5.rst
index bea6a8a..ae18276 100644
--- a/Doc/whatsnew/3.5.rst
+++ b/Doc/whatsnew/3.5.rst
@@ -118,7 +118,9 @@ Other Language Changes
 
 Some smaller changes made to the core Python language are:
 
-* None yet.
+* Added the ``'namereplace'`` error handlers.  The ``'backslashreplace'``
+  error handlers now works with decoding and translating.
+  (Contributed by Serhiy Storchaka in :issue:`19676` and :issue:`22286`.)