.. bpo: 38945
.. date: 2019-12-01-22-44-40
.. nonce: ztmNXc
.. release date: 2019-12-11
.. section: Security

Newline characters have been escaped when performing uu encoding to prevent
them from overflowing into to content section of the encoded file. This
prevents malicious or accidental modification of data during the decoding
process.

..

.. bpo: 37228
.. date: 2019-11-21-21-36-54
.. nonce: yBZnFG
.. section: Security

Due to significant security concerns, the *reuse_address* parameter of
:meth:`asyncio.loop.create_datagram_endpoint` is no longer supported. This
is because of the behavior of ``SO_REUSEADDR`` in UDP. For more details, see
the documentation for ``loop.create_datagram_endpoint()``. (Contributed by
Kyle Stanley, Antoine Pitrou, and Yury Selivanov in :issue:`37228`.)

..

.. bpo: 38804
.. date: 2019-11-15-00-54-42
.. nonce: vjbM8V
.. section: Security

Fixes a ReDoS vulnerability in :mod:`http.cookiejar`. Patch by Ben Caller.

..

.. bpo: 38673
.. date: 2019-12-01-00-17-44
.. nonce: K_Tze-
.. section: Core and Builtins

In REPL mode, don't switch to PS2 if the line starts with comment or
whitespace. Based on work by Batuhan Taşkaya.

..

.. bpo: 38535
.. date: 2019-10-20-12-43-48
.. nonce: ESMkVN
.. section: Core and Builtins

Fixed line numbers and column offsets for AST nodes for calls without
arguments in decorators.

..

.. bpo: 38379
.. date: 2019-10-09-16-50-52
.. nonce: oz5qZx
.. section: Core and Builtins

When cyclic garbage collection (gc) runs finalizers that resurrect
unreachable objects, the current gc run ends, without collecting any cyclic
trash.  However, the statistics reported by ``collect()`` and
``get_stats()`` claimed that all cyclic trash found was collected, and that
the resurrected objects were collected.   Changed the stats to report that
none were collected.

..

.. bpo: 35409
.. date: 2019-07-13-18-01-13
.. nonce: ozbcsR
.. section: Core and Builtins

Ignore GeneratorExit exceptions when throwing an exception into the aclose
coroutine of an asynchronous generator.

..

.. bpo: 39006
.. date: 2019-12-09-14-40-09
.. nonce: v4VsPg
.. section: Library

Fix asyncio when the ssl module is missing: only check for ssl.SSLSocket
instance if the ssl module is available.

..

.. bpo: 38979
.. date: 2019-12-07-16-32-42
.. nonce: q0sIHy
.. section: Library

Return class from ``ContextVar.__class_getitem__`` to simplify subclassing.

..

.. bpo: 38986
.. date: 2019-12-06-15-11-42
.. nonce: bg6iZt
.. section: Library

Make repr of C accelerated TaskWakeupMethWrapper the same as of pure Python
version.

..

.. bpo: 33684
.. date: 2019-12-04-15-28-40
.. nonce: QeSmQP
.. section: Library

Fix ``json.tool`` failed to read a JSON file with non-ASCII characters when
locale encoding is not UTF-8.

..

.. bpo: 26730
.. date: 2019-11-27-16-30-02
.. nonce: 56cdBn
.. section: Library

Fix ``SpooledTemporaryFile.rollover()`` might corrupt the file when it is in
text mode. Patch by Serhiy Storchaka.

..

.. bpo: 37838
.. date: 2019-11-21-11-39-17
.. nonce: lRFcEC
.. section: Library

:meth:`typing.get_type_hints` properly handles functions decorated with
:meth:`functools.wraps`.

..

.. bpo: 38821
.. date: 2019-11-16-23-26-25
.. nonce: -albNN
.. section: Library

Fix unhandled exceptions in :mod:`argparse` when internationalizing error
messages for arguments with ``nargs`` set to special (non-integer) values.
Patch by Federico Bond.

..

.. bpo: 38820
.. date: 2019-11-16-16-09-07
.. nonce: ivhUSV
.. section: Library

Make Python compatible with OpenSSL 3.0.0. :func:`ssl.SSLSocket.getpeercert`
no longer returns IPv6 addresses with a trailing new line.

..

.. bpo: 38785
.. date: 2019-11-13-16-17-43
.. nonce: NEOEfk
.. section: Library

Prevent asyncio from crashing if parent ``__init__`` is not called from a
constructor of object derived from ``asyncio.Future``.

..

.. bpo: 27805
.. date: 2019-11-11-21-43-06
.. nonce: D3zl1_
.. section: Library

Allow opening pipes and other non-seekable files in append mode with
:func:`open`.

..

.. bpo: 38686
.. date: 2019-11-06-15-26-15
.. nonce: HNFBce
.. section: Library

Added support for multiple ``qop`` values in
:class:`urllib.request.AbstractDigestAuthHandler`.

..

.. bpo: 38334
.. date: 2019-10-27-00-08-49
.. nonce: pfLLmc
.. section: Library

Fixed seeking backward on an encrypted :class:`zipfile.ZipExtFile`.

..

.. bpo: 31202
.. date: 2019-10-20-12-04-48
.. nonce: NfdIus
.. section: Library

The case the result of :func:`pathlib.WindowsPath.glob` matches now the case
of the pattern for literal parts.

..

.. bpo: 38109
.. date: 2019-10-10-00-25-28
.. nonce: 9w-IGF
.. section: Library

Add missing :data:`stat.S_IFDOOR`, :data:`stat.S_IFPORT`,
:data:`stat.S_IFWHT`, :func:`stat.S_ISDOOR`, :func:`stat.S_ISPORT`, and
:func:`stat.S_ISWHT` values to the Python implementation of :mod:`stat`.

..

.. bpo: 38422
.. date: 2019-10-09-18-16-51
.. nonce: aiM5bq
.. section: Library

Clarify docstrings of pathlib suffix(es)

..

.. bpo: 38405
.. date: 2019-10-08-11-18-40
.. nonce: 0-7e7s
.. section: Library

Nested subclasses of :class:`typing.NamedTuple` are now pickleable.

..

.. bpo: 38332
.. date: 2019-10-05-02-07-52
.. nonce: hwrPN7
.. section: Library

Prevent :exc:`KeyError` thrown by :func:`_encoded_words.decode` when given
an encoded-word with invalid content-type encoding from propagating all the
way to :func:`email.message.get`.

..

.. bpo: 38341
.. date: 2019-10-01-21-06-18
.. nonce: uqwgU_
.. section: Library

Add :exc:`smtplib.SMTPNotSupportedError` to the :mod:`smtplib` exported
names.

..

.. bpo: 13153
.. date: 2019-09-29-22-47-37
.. nonce: 0mO9qR
.. section: Library

OS native encoding is now used for converting between Python strings and Tcl
objects.  This allows to display, copy and paste to clipboard emoji and
other non-BMP characters.  Converting strings from Tcl to Python and back
now never fails (except MemoryError).

..

.. bpo: 36993
.. date: 2019-07-09-05-44-39
.. nonce: 4javqu
.. section: Library

Improve error reporting for corrupt zip files with bad zip64 extra data.
Patch by Daniel Hillier.

..

.. bpo: 36952
.. date: 2019-05-20-08-54-41
.. nonce: I_glok
.. section: Library

Starting with Python 3.3, importing ABCs from :mod:`collections` is
deprecated, and import should be done from :mod:`collections.abc`. Still
being able to import from :mod:`collections` was marked for removal in 3.8,
but has been delayed to 3.9; documentation and ``DeprecationWarning``
clarified.

..

.. bpo: 36820
.. date: 2019-05-06-15-34-17
.. nonce: Eh5mIB
.. section: Library

Break cycle generated when saving an exception in socket.py, codeop.py and
dyld.py as they keep alive not only the exception but user objects through
the ``__traceback__`` attribute. Patch by Mario Corchero.

..

.. bpo: 34776
.. date: 2018-09-23-14-24-37
.. nonce: 1SrQe3
.. section: Library

Fix dataclasses to support forward references in type annotations

..

.. bpo: 33348
.. date: 2018-04-24-13-18-48
.. nonce: XaJDei
.. section: Library

lib2to3 now recognizes expressions after ``*`` and `**` like in ``f(*[] or
[])``.

..

.. bpo: 27657
.. date: 2017-12-26-14-32-23
.. nonce: 6BhyVK
.. section: Library

Fix urllib.parse.urlparse() with numeric paths. A string like "path:80" is
no longer parsed as a path but as a scheme ("path") and a path ("80").

..

.. bpo: 38351
.. date: 2019-11-15-09-22-28
.. nonce: xwhlse
.. section: Documentation

Modernize :mod:`email` examples from %-formatting to f-strings.

..

.. bpo: 38592
.. date: 2019-10-26-13-19-07
.. nonce: Y96BYO
.. section: Documentation

Add Brazilian Portuguese to the language switcher at Python Documentation
website.

..

.. bpo: 38294
.. date: 2019-09-27-23-37-41
.. nonce: go_jFf
.. section: Documentation

Add list of no-longer-escaped chars to re.escape documentation

..

.. bpo: 38547
.. date: 2019-12-09-11-32-34
.. nonce: Juw54e
.. section: Tests

Fix test_pty: if the process is the session leader, closing the master file
descriptor raises a SIGHUP signal: simply ignore SIGHUP when running the
tests.

..

.. bpo: 38965
.. date: 2019-12-04-17-08-55
.. nonce: yqax3m
.. section: Tests

Fix test_faulthandler on GCC 10. Use the "volatile" keyword in
``faulthandler._stack_overflow()`` to prevent tail call optimization on any
compiler, rather than relying on compiler specific pragma.

..

.. bpo: 38669
.. date: 2019-11-04-02-54-16
.. nonce: pazXZ8
.. section: Tests

Raise :exc:`TypeError` when passing target as a string with
:meth:`unittest.mock.patch.object`.

..

.. bpo: 35998
.. date: 2019-10-16-01-36-15
.. nonce: G305Bf
.. section: Tests

Fix a race condition in test_asyncio.test_start_tls_server_1(). Previously,
there was a race condition between the test main() function which replaces
the protocol and the test ServerProto protocol which sends ANSWER once it
gets HELLO. Now, only the test main() function is responsible to send data,
ServerProto no longer sends data.

..

.. bpo: 37531
.. date: 2019-10-08-16-42-05
.. nonce: 7v-_Ca
.. section: Tests

On timeout, regrtest no longer attempts to call ``popen.communicate()``
again: it can hang until all child processes using stdout and stderr pipes
completes. Kill the worker process and ignores its output. Change also the
faulthandler timeout of the main process from 1 minute to 5 minutes, for
Python slowest buildbots.

..

.. bpo: 37404
.. date: 2019-12-01-21-45-24
.. nonce: cNsA7S
.. section: Build

:mod:`asyncio` now raises :exc:`TyperError` when calling incompatible
methods with an :class:`ssl.SSLSocket` socket.  Patch by Ido Michael.

..

.. bpo: 38809
.. date: 2019-11-15-09-25-44
.. nonce: 9jwta6
.. section: Build

On Windows, build scripts will now recognize and use python.exe from an
active virtual env.

..

.. bpo: 37415
.. date: 2019-10-11-15-32-58
.. nonce: D9RXrq
.. section: Build

Fix stdatomic.h header check for ICC compiler: the ICC implementation lacks
atomic_uintptr_t type which is needed by Python.

..

.. bpo: 38589
.. date: 2019-10-28-10-48-16
.. nonce: V69Q1a
.. section: Windows

Fixes HTML Help shortcut when Windows is not installed to C drive

..

.. bpo: 38944
.. date: 2019-11-30-12-10-36
.. nonce: _3xjKG
.. section: IDLE

Excape key now closes IDLE completion windows.  Patch by Johnny Najera.

..

.. bpo: 38943
.. date: 2019-11-29-23-44-11
.. nonce: 8pUKKs
.. section: IDLE

Fix IDLE autocomplete windows not always appearing on some systems. Patch by
Johnny Najera.

..

.. bpo: 38862
.. date: 2019-11-23-21-50-57
.. nonce: KQ9A0m
.. section: IDLE

'Strip Trailing Whitespace' on the Format menu removes extra newlines at the
end of non-shell files.

..

.. bpo: 26353
.. date: 2019-11-09-23-55-59
.. nonce: duYZiF
.. section: IDLE

Stop adding newline when saving an IDLE shell window.

..

.. bpo: 38636
.. date: 2019-10-30-22-11-16
.. nonce: hUhDeB
.. section: IDLE

Fix IDLE Format menu tab toggle and file indent width. These functions
(default shortcuts Alt-T and Alt-U) were mistakenly disabled in 3.7.5 and
3.8.0.

..

.. bpo: 4630
.. date: 2019-10-28-04-48-03
.. nonce: upgjiV
.. section: IDLE

Add an option to toggle IDLE's cursor blink for shell, editor, and output
windows.  See Settings, General, Window Preferences, Cursor Blink. Patch by
Zachary Spytz.

..

.. bpo: 38598
.. date: 2019-10-26-18-16-24
.. nonce: 6kH9FY
.. section: IDLE

Do not try to compile IDLE shell or output windows

..

.. bpo: 36698
.. date: 2019-10-04-18-03-09
.. nonce: BKcmom
.. section: IDLE

IDLE no longer fails when write non-encodable characters to stderr.  It now
escapes them with a backslash, as the regular Python interpreter. Added the
``errors`` field to the standard streams.

..

.. bpo: 38118
.. date: 2019-10-08-15-07-52
.. nonce: pIZD6H
.. section: Tools/Demos

Update Valgrind suppression file to ignore a false alarm in
:c:func:`PyUnicode_Decode` when using GCC builtin strcmp().

..

.. bpo: 38347
.. date: 2019-10-02-09-48-42
.. nonce: 2Tq5D1
.. section: Tools/Demos

pathfix.py: Assume all files that end on '.py' are Python scripts when
working recursively.

..

.. bpo: 38540
.. date: 2019-10-21-09-24-03
.. nonce: 314N_T
.. section: C API

Fixed possible leak in :c:func:`PyArg_Parse` and similar functions for
format units ``"es#"`` and ``"et#"`` when the macro
:c:macro:`PY_SSIZE_T_CLEAN` is not defined.

..

.. bpo: 38395
.. date: 2019-10-08-01-23-24
.. nonce: MJ6Ey9
.. section: C API

Fix a crash in :class:`weakref.proxy` objects due to incorrect lifetime
management when calling some associated methods that may delete the last
reference to object being referenced by the proxy. Patch by Pablo Galindo.