.. bpo: 39401
.. date: 2020-01-28-20-54-09
.. nonce: he7h_A
.. release date: 2020-03-04
.. section: Security

Avoid unsafe load of ``api-ms-win-core-path-l1-1-0.dll`` at startup on
Windows 7.

..

.. bpo: 39776
.. date: 2020-03-02-20-12-33
.. nonce: fNaxi_
.. section: Core and Builtins

Fix race condition where threads created by PyGILState_Ensure() could get a
duplicate id.

This affects consumers of tstate->id like the contextvar caching machinery,
which could return invalid cached objects under heavy thread load (observed
in embedded scenarios).

..

.. bpo: 39778
.. date: 2020-03-02-19-21-21
.. nonce: _YGLEc
.. section: Core and Builtins

Fixed a crash due to incorrect handling of weak references in
``collections.OrderedDict`` classes. Patch by Pablo Galindo.

..

.. bpo: 39382
.. date: 2020-02-18-01-40-13
.. nonce: OLSJu9
.. section: Core and Builtins

Fix a use-after-free in the single inheritance path of ``issubclass()``,
when the ``__bases__`` of an object has a single reference, and so does its
first item. Patch by Yonatan Goldschmidt.

..

.. bpo: 39606
.. date: 2020-02-11-23-59-07
.. nonce: a72Sxc
.. section: Core and Builtins

Fix regression caused by fix for bpo-39386, that prevented calling
``aclose`` on an async generator that had already been closed or exhausted.

..

.. bpo: 39510
.. date: 2020-02-04-10-27-41
.. nonce: PMIh-f
.. section: Core and Builtins

Fix segfault in ``readinto()`` method on closed BufferedReader.

..

.. bpo: 39453
.. date: 2020-01-25-23-51-17
.. nonce: xCOkYk
.. section: Core and Builtins

Fixed a possible crash in :meth:`list.__contains__` when a list is changed
during comparing items. Patch by Dong-hee Na.

..

.. bpo: 39427
.. date: 2020-01-22-22-28-04
.. nonce: LiO-Eo
.. section: Core and Builtins

Document all possibilities for the ``-X`` options in the command line help
section. Patch by Pablo Galindo.

..

.. bpo: 39421
.. date: 2020-01-22-15-53-37
.. nonce: O3nG7u
.. section: Core and Builtins

Fix possible crashes when operating with the functions in the :mod:`heapq`
module and custom comparison operators.

..

.. bpo: 39386
.. date: 2020-01-20-21-40-57
.. nonce: ULqD8t
.. section: Core and Builtins

Prevent double awaiting of async iterator.

..

.. bpo: 38588
.. date: 2019-12-29-19-13-54
.. nonce: pgXnNS
.. section: Core and Builtins

Fix possible crashes in dict and list when calling
:c:func:`PyObject_RichCompareBool`.

..

.. bpo: 39031
.. date: 2019-12-12-21-05-43
.. nonce: imlCYZ
.. section: Core and Builtins

When parsing an "elif" node, lineno and col_offset of the node now point to
the "elif" keyword and not to its condition, making it consistent with the
"if" node. Patch by Lysandros Nikolaou.

..

.. bpo: 38610
.. date: 2019-10-31-14-30-39
.. nonce: fHdVMS
.. section: Core and Builtins

Fix possible crashes in several list methods by holding strong references to
list elements when calling :c:func:`PyObject_RichCompareBool`.

..

.. bpo: 39794
.. date: 2020-02-29-19-17-39
.. nonce: 7VjatS
.. section: Library

Add --without-decimal-contextvar build option.  This enables a thread-local
rather than a coroutine local context.

..

.. bpo: 39769
.. date: 2020-02-29-13-20-33
.. nonce: hJmxu4
.. section: Library

The :func:`compileall.compile_dir` function's *ddir* parameter and the
compileall command line flag `-d` no longer write the wrong pathname to the
generated pyc file for submodules beneath the root of the directory tree
being compiled.  This fixes a regression introduced with Python 3.5.

..

.. bpo: 30566
.. date: 2020-02-24-03-45-28
.. nonce: qROxty
.. section: Library

Fix :exc:`IndexError` when trying to decode an invalid string with punycode
codec.

..

.. bpo: 39649
.. date: 2020-02-23-21-27-10
.. nonce: qiubSp
.. section: Library

Remove obsolete check for `__args__` in bdb.Bdb.format_stack_entry.

..

.. bpo: 27657
.. date: 2020-02-16-07-47-55
.. nonce: 9kZchc
.. section: Library

The original fix for bpo-27657, "Fix urlparse() with numeric paths"
(GH-16839) included in 3.7.6, inadvertently introduced a behavior change
that broke several third-party packages relying on the original undefined
parsing behavior. The change is reverted in 3.7.7, restoring the behavior of
3.7.5 and earlier releases.

..

.. bpo: 21016
.. date: 2020-02-12-10-04-39
.. nonce: bFXPH7
.. section: Library

The :mod:`pydoc` and :mod:`trace` modules now use the :mod:`sysconfig`
module to get the path to the Python standard library, to support uncommon
installation path like ``/usr/lib64/python3.9/`` on Fedora. Patch by Jan
Matějek.

..

.. bpo: 39548
.. date: 2020-02-06-05-33-52
.. nonce: DF4FFe
.. section: Library

Fix handling of header in :class:`urllib.request.AbstractDigestAuthHandler`
when the optional ``qop`` parameter is not present.

..

.. bpo: 39450
.. date: 2020-02-02-14-46-34
.. nonce: 48R274
.. section: Library

Striped whitespace from docstring before returning it from
:func:`unittest.case.shortDescription`.

..

.. bpo: 39493
.. date: 2020-01-30-01-13-19
.. nonce: CbFRi7
.. section: Library

Mark ``typing.IO.closed`` as a property

..

.. bpo: 39485
.. date: 2020-01-29-14-58-27
.. nonce: Zy3ot6
.. section: Library

Fix a bug in :func:`unittest.mock.create_autospec` that would complain about
the wrong number of arguments for custom descriptors defined in an extension
module returning functions.

..

.. bpo: 39430
.. date: 2020-01-24-11-05-21
.. nonce: I0UQzM
.. section: Library

Fixed race condition in lazy imports in :mod:`tarfile`.

..

.. bpo: 39389
.. date: 2020-01-20-00-56-01
.. nonce: fEirIS
.. section: Library

Write accurate compression level metadata in :mod:`gzip` archives, rather
than always signaling maximum compression.

..

.. bpo: 39274
.. date: 2020-01-15-23-13-03
.. nonce: lpc0-n
.. section: Library

``bool(fraction.Fraction)`` now returns a boolean even if (numerator != 0)
does not return a boolean (ex: numpy number).

..

.. bpo: 39242
.. date: 2020-01-08-23-25-27
.. nonce: bnL65N
.. section: Library

Updated the Gmane domain from news.gmane.org to news.gmane.io which is used
for examples of :class:`~nntplib.NNTP` news reader server and nntplib tests.

..

.. bpo: 39152
.. date: 2020-01-03-18-02-50
.. nonce: JgPjCC
.. section: Library

Fix ttk.Scale.configure([name]) to return configuration tuple for name or
all options.  Giovanni Lombardo contributed part of the patch.

..

.. bpo: 39198
.. date: 2020-01-02-20-21-03
.. nonce: nzwGyG
.. section: Library

If an exception were to be thrown in `Logger.isEnabledFor` (say, by asyncio
timeouts or stopit) , the `logging` global lock may not be released
appropriately, resulting in deadlock.  This change wraps that block of code
with `try...finally` to ensure the lock is released.

..

.. bpo: 39191
.. date: 2020-01-02-17-28-03
.. nonce: ur_scy
.. section: Library

Perform a check for running loop before starting a new task in
``loop.run_until_complete()`` to fail fast; it prevents the side effect of
new task spawning before exception raising.

..

.. bpo: 38871
.. date: 2020-01-01-18-44-52
.. nonce: 3EEOLg
.. section: Library

Correctly parenthesize filter-based statements that contain lambda
expressions in mod:`lib2to3`. Patch by Dong-hee Na.

..

.. bpo: 39142
.. date: 2019-12-31-19-27-23
.. nonce: oqU5iD
.. section: Library

A change was made to logging.config.dictConfig to avoid converting instances
of named tuples to ConvertingTuple. It's assumed that named tuples are too
specialised to be treated like ordinary tuples; if a user of named tuples
requires ConvertingTuple functionality, they will have to implement that
themselves in their named tuple class.

..

.. bpo: 38971
.. date: 2019-12-20-16-06-28
.. nonce: fKRYlF
.. section: Library

Open issue in the BPO indicated a desire to make the implementation of
codecs.open() at parity with io.open(), which implements a try/except to
assure file stream gets closed before an exception is raised.

..

.. bpo: 39057
.. date: 2019-12-15-21-47-54
.. nonce: FOxn-w
.. section: Library

:func:`urllib.request.proxy_bypass_environment` now ignores leading dots and
no longer ignores a trailing newline.

..

.. bpo: 39056
.. date: 2019-12-15-21-05-16
.. nonce: nEfUM9
.. section: Library

Fixed handling invalid warning category in the -W option.  No longer import
the re module if it is not needed.

..

.. bpo: 39055
.. date: 2019-12-15-19-23-23
.. nonce: FmN3un
.. section: Library

:func:`base64.b64decode` with ``validate=True`` raises now a binascii.Error
if the input ends with a single ``\n``.

..

.. bpo: 38878
.. date: 2019-11-22-12-08-52
.. nonce: EJ0cFf
.. section: Library

Fixed __subclasshook__ of :class:`os.PathLike` to return a correct result
upon inheritence. Patch by Bar Harel.

..

.. bpo: 35182
.. date: 2019-10-31-19-23-25
.. nonce: hzeNl9
.. section: Library

Fixed :func:`Popen.communicate` subsequent call crash when the child process
has already closed any piped standard stream, but still continues to be
running. Patch by Andriy Maletsky.

..

.. bpo: 38473
.. date: 2019-10-14-21-14-55
.. nonce: uXpVld
.. section: Library

Use signature from inner mock for autospecced methods attached with
:func:`unittest.mock.attach_mock`. Patch by Karthikeyan Singaravelan.

..

.. bpo: 38293
.. date: 2019-09-29-08-17-03
.. nonce: wls5s3
.. section: Library

Add :func:`copy.copy` and :func:`copy.deepcopy` support to :func:`property`
objects.

..

.. bpo: 37953
.. date: 2019-09-06-17-40-34
.. nonce: db5FQq
.. section: Library

In :mod:`typing`, improved the ``__hash__`` and ``__eq__`` methods for
:class:`ForwardReferences`.

..

.. bpo: 36406
.. date: 2019-03-24-12-12-27
.. nonce: mCEkOl
.. section: Library

Handle namespace packages in :mod:`doctest`. Patch by Karthikeyan
Singaravelan.

..

.. bpo: 13790
.. date: 2020-02-28-14-39-25
.. nonce: hvLaRI
.. section: Documentation

Change 'string' to 'specification' in format doc.

..

.. bpo: 39530
.. date: 2020-02-23-13-26-40
.. nonce: _bCvzQ
.. section: Documentation

Fix misleading documentation about mixed-type numeric comparisons.

..

.. bpo: 17422
.. date: 2020-02-19-11-13-47
.. nonce: g7_9zz
.. section: Documentation

The language reference now specifies restrictions on class namespaces.
Adapted from a patch by Ethan Furman.

..

.. bpo: 39654
.. date: 2020-02-18-07-42-20
.. nonce: MoT1jI
.. section: Documentation

In pyclbr doc, update 'class' to 'module' where appropriate and add
readmodule comment. Patch by Hakan Çelik.

..

.. bpo: 39392
.. date: 2020-01-27-18-18-42
.. nonce: oiqcLO
.. section: Documentation

Explain that when filling with turtle, overlap regions may be left unfilled.

..

.. bpo: 39381
.. date: 2020-01-18-15-37-56
.. nonce: wTWe8d
.. section: Documentation

Mention in docs that :func:`asyncio.get_event_loop` implicitly creates new
event loop only if called from the main thread.

..

.. bpo: 38918
.. date: 2019-12-15-22-04-41
.. nonce: 8JnDTS
.. section: Documentation

Add an entry for ``__module__`` in the "function" & "method" sections of the
`inspect docs types and members table
<https://docs.python.org/3/library/inspect.html#types-and-members>`_

..

.. bpo: 3530
.. date: 2019-11-17-11-53-10
.. nonce: 8zFUMc
.. section: Documentation

In the :mod:`ast` module documentation, fix a misleading ``NodeTransformer``
example and add advice on when to use the ``fix_missing_locations``
function.

..

.. bpo: 38546
.. date: 2019-12-18-14-52-08
.. nonce: 2kxNuM
.. section: Tests

Fix test_ressources_gced_in_workers() of test_concurrent_futures: explicitly
stop the manager to prevent leaking a child process running in the
background after the test completes.

..

.. bpo: 39144
.. date: 2019-12-27-22-18-26
.. nonce: dwHMlR
.. section: Build

The ctags and etags build targets both include Modules/_ctypes and Python
standard library source files.

..

.. bpo: 38597
.. date: 2020-03-01-15-04-54
.. nonce: MnHdYl
.. section: Windows

:mod:`distutils` will no longer statically link :file:`vcruntime140.dll`
when a redistributable version is unavailable. All future releases of
CPython will include a copy of this DLL to ensure distributed extensions can
continue to load.

..

.. bpo: 38380
.. date: 2020-02-28-23-51-27
.. nonce: TpOBCj
.. section: Windows

Update Windows builds to use SQLite 3.31.1

..

.. bpo: 39439
.. date: 2020-01-24-03-07-14
.. nonce: rwMWDR
.. section: Windows

Reduce overhead when using multiprocessing in a Windows virtual environment

..

.. bpo: 39185
.. date: 2020-01-02-01-11-53
.. nonce: T4herN
.. section: Windows

The build.bat script has additional options for very-quiet output (-q) and
very-verbose output (-vv)

..

.. bpo: 38380
.. date: 2020-02-28-23-51-47
.. nonce: u-ySyA
.. section: macOS

Update macOS builds to use SQLite 3.31.1

..

.. bpo: 39781
.. date: 2020-02-27-22-17-09
.. nonce: bbYBeL
.. section: IDLE

Selecting code context lines no longer causes a jump.

..

.. bpo: 39663
.. date: 2020-02-17-21-09-03
.. nonce: wexcsH
.. section: IDLE

Add tests for pyparse find_good_parse_start().

..

.. bpo: 39600
.. date: 2020-02-10-17-09-48
.. nonce: X6NsyM
.. section: IDLE

In the font configuration window, remove duplicated font names.

..

.. bpo: 30780
.. date: 2020-01-27-16-44-29
.. nonce: nR80qu
.. section: IDLE

Add remaining configdialog tests for buttons and highlights and keys tabs.

..

.. bpo: 39388
.. date: 2020-01-25-02-26-45
.. nonce: x4TQNh
.. section: IDLE

IDLE Settings Cancel button now cancels pending changes

..

.. bpo: 39050
.. date: 2020-01-22-22-28-06
.. nonce: zkn0FO
.. section: IDLE

Make IDLE Settings dialog Help button work again.

..

.. bpo: 34118
.. date: 2019-12-30-16-44-07
.. nonce: FaNW0a
.. section: IDLE

Tag memoryview, range, and tuple as classes, the same as list, etcetera, in
the library manual built-in functions list.

..

.. bpo: 38792
.. date: 2019-11-13-23-51-39
.. nonce: xhTC5a
.. section: IDLE

Close an IDLE shell calltip if a :exc:`KeyboardInterrupt` or shell restart
occurs.  Patch by Zackery Spytz.

..

.. bpo: 32989
.. date: 2018-03-03-12-56-26
.. nonce: FVhmhH
.. section: IDLE

Add tests for editor newline_and_indent_event method. Remove dead code from
pyparse find_good_parse_start method.