18 files changed, 181 insertions, 51 deletions
diff --git a/Doc/c-api/init.rst b/Doc/c-api/init.rst
index 41fd4ea14ef..409539dec17 100644
--- a/Doc/c-api/init.rst
+++ b/Doc/c-api/init.rst
@@ -2277,6 +2277,18 @@ The C-API provides a basic mutual exclusion lock.
 
    .. versionadded:: 3.13
 
+.. c:function:: int PyMutex_IsLocked(PyMutex *m)
+
+   Returns non-zero if the mutex *m* is currently locked, zero otherwise.
+
+   .. note::
+
+      This function is intended for use in assertions and debugging only and
+      should not be used to make concurrency control decisions, as the lock
+      state may change immediately after the check.
+
+   .. versionadded:: next
+
 .. _python-critical-section-api:
 
 Python Critical Section API
diff --git a/Doc/c-api/object.rst b/Doc/c-api/object.rst
index 0fd159f1eb8..21fa1491b33 100644
--- a/Doc/c-api/object.rst
+++ b/Doc/c-api/object.rst
@@ -197,6 +197,13 @@ Object Protocol
    in favour of using :c:func:`PyObject_DelAttr`, but there are currently no
    plans to remove it.
 
+   The function must not be called with ``NULL`` *v* and an an exception set.
+   This case can arise from forgetting ``NULL`` checks and would delete the
+   attribute.
+
+   .. versionchanged:: next
+      Must not be called with NULL value if an exception is set.
+
 
 .. c:function:: int PyObject_SetAttrString(PyObject *o, const char *attr_name, PyObject *v)
 
@@ -207,6 +214,10 @@ Object Protocol
    If *v* is ``NULL``, the attribute is deleted, but this feature is
    deprecated in favour of using :c:func:`PyObject_DelAttrString`.
 
+   The function must not be called with ``NULL`` *v* and an an exception set.
+   This case can arise from forgetting ``NULL`` checks and would delete the
+   attribute.
+
    The number of different attribute names passed to this function
    should be kept small, usually by using a statically allocated string
    as *attr_name*.
@@ -215,6 +226,10 @@ Object Protocol
    For more details, see :c:func:`PyUnicode_InternFromString`, which may be
    used internally to create a key object.
 
+   .. versionchanged:: next
+      Must not be called with NULL value if an exception is set.
+
+
 .. c:function:: int PyObject_GenericSetAttr(PyObject *o, PyObject *name, PyObject *value)
 
    Generic attribute setter and deleter function that is meant
diff --git a/Doc/deprecations/c-api-pending-removal-in-3.15.rst b/Doc/deprecations/c-api-pending-removal-in-3.15.rst
index b87f0a5ecde..a3e335ecaf4 100644
--- a/Doc/deprecations/c-api-pending-removal-in-3.15.rst
+++ b/Doc/deprecations/c-api-pending-removal-in-3.15.rst
@@ -1,7 +1,6 @@
 Pending removal in Python 3.15
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-* The bundled copy of ``libmpdecimal``.
 * The :c:func:`!PyImport_ImportModuleNoBlock`:
   Use :c:func:`PyImport_ImportModule` instead.
 * :c:func:`PyWeakref_GetObject` and :c:func:`PyWeakref_GET_OBJECT`:
diff --git a/Doc/deprecations/c-api-pending-removal-in-3.16.rst b/Doc/deprecations/c-api-pending-removal-in-3.16.rst
new file mode 100644
index 00000000000..9453f83799c
--- /dev/null
+++ b/Doc/deprecations/c-api-pending-removal-in-3.16.rst
@@ -0,0 +1,4 @@
+Pending removal in Python 3.16
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+* The bundled copy of ``libmpdec``.
diff --git a/Doc/howto/functional.rst b/Doc/howto/functional.rst
index 78e56e0c64f..053558e3890 100644
--- a/Doc/howto/functional.rst
+++ b/Doc/howto/functional.rst
@@ -1217,7 +1217,7 @@ flow inside a program.  The book uses Scheme for its examples, but many of the
 design approaches described in these chapters are applicable to functional-style
 Python code.
 
-https://www.defmacro.org/ramblings/fp.html: A general introduction to functional
+https://defmacro.org/2006/06/19/fp.html: A general introduction to functional
 programming that uses Java examples and has a lengthy historical introduction.
 
 https://en.wikipedia.org/wiki/Functional_programming: General Wikipedia entry
diff --git a/Doc/howto/isolating-extensions.rst b/Doc/howto/isolating-extensions.rst
index fbc426ba1d7..7da6dc8a397 100644
--- a/Doc/howto/isolating-extensions.rst
+++ b/Doc/howto/isolating-extensions.rst
@@ -626,8 +626,7 @@ Open Issues
 
 Several issues around per-module state and heap types are still open.
 
-Discussions about improving the situation are best held on the `capi-sig
-mailing list <https://mail.python.org/mailman3/lists/capi-sig.python.org/>`__.
+Discussions about improving the situation are best held on the `discuss forum under c-api tag <https://discuss.python.org/c/core-dev/c-api/30>`__.
 
 
 Per-Class Scope
diff --git a/Doc/installing/index.rst b/Doc/installing/index.rst
index a46c1caefe4..3a485a43a5a 100644
--- a/Doc/installing/index.rst
+++ b/Doc/installing/index.rst
@@ -188,7 +188,7 @@ switch::
    Once the Development & Deployment part of PPUG is fleshed out, some of
    those sections should be linked from new questions here (most notably,
    we should have a question about avoiding depending on PyPI that links to
-   https://packaging.python.org/en/latest/mirrors/)
+   https://packaging.python.org/en/latest/guides/index-mirrors-and-caches/)
 
 
 Common installation issues
diff --git a/Doc/library/compression.zstd.rst b/Doc/library/compression.zstd.rst
index 57ad8e3377f..a901403621b 100644
--- a/Doc/library/compression.zstd.rst
+++ b/Doc/library/compression.zstd.rst
@@ -523,8 +523,14 @@ Advanced parameter control
    .. attribute:: compression_level
 
       A high-level means of setting other compression parameters that affect
-      the speed and ratio of compressing data. Setting the level to zero uses
-      :attr:`COMPRESSION_LEVEL_DEFAULT`.
+      the speed and ratio of compressing data.
+
+      Regular compression levels are greater than ``0``. Values greater than
+      ``20`` are considered "ultra" compression and require more memory than
+      other levels. Negative values can be used to trade off faster compression
+      for worse compression ratios.
+
+      Setting the level to zero uses :attr:`COMPRESSION_LEVEL_DEFAULT`.
 
    .. attribute:: window_log
 
diff --git a/Doc/library/shutil.rst b/Doc/library/shutil.rst
index 2dde40c9d92..dde38498206 100644
--- a/Doc/library/shutil.rst
+++ b/Doc/library/shutil.rst
@@ -618,7 +618,8 @@ provided.  They rely on the :mod:`zipfile` and :mod:`tarfile` modules.
    *format* is the archive format: one of
    "zip" (if the :mod:`zlib` module is available), "tar", "gztar" (if the
    :mod:`zlib` module is available), "bztar" (if the :mod:`bz2` module is
-   available), or "xztar" (if the :mod:`lzma` module is available).
+   available), "xztar" (if the :mod:`lzma` module is available), or "zstdtar"
+   (if the :mod:`compression.zstd` module is available).
 
    *root_dir* is a directory that will be the root directory of the
    archive, all paths in the archive will be relative to it; for example,
@@ -673,6 +674,8 @@ provided.  They rely on the :mod:`zipfile` and :mod:`tarfile` modules.
    - *gztar*: gzip'ed tar-file (if the :mod:`zlib` module is available).
    - *bztar*: bzip2'ed tar-file (if the :mod:`bz2` module is available).
    - *xztar*: xz'ed tar-file (if the :mod:`lzma` module is available).
+   - *zstdtar*: Zstandard compressed tar-file (if the :mod:`compression.zstd`
+     module is available).
 
    You can register new formats or provide your own archiver for any existing
    formats, by using :func:`register_archive_format`.
@@ -716,8 +719,8 @@ provided.  They rely on the :mod:`zipfile` and :mod:`tarfile` modules.
    *extract_dir* is the name of the target directory where the archive is
    unpacked. If not provided, the current working directory is used.
 
-   *format* is the archive format: one of "zip", "tar", "gztar", "bztar", or
-   "xztar".  Or any other format registered with
+   *format* is the archive format: one of "zip", "tar", "gztar", "bztar",
+   "xztar", or "zstdtar".  Or any other format registered with
    :func:`register_unpack_format`.  If not provided, :func:`unpack_archive`
    will use the archive file name extension and see if an unpacker was
    registered for that extension.  In case none is found,
@@ -789,6 +792,8 @@ provided.  They rely on the :mod:`zipfile` and :mod:`tarfile` modules.
    - *gztar*: gzip'ed tar-file (if the :mod:`zlib` module is available).
    - *bztar*: bzip2'ed tar-file (if the :mod:`bz2` module is available).
    - *xztar*: xz'ed tar-file (if the :mod:`lzma` module is available).
+   - *zstdtar*: Zstandard compressed tar-file (if the :mod:`compression.zstd`
+     module is available).
 
    You can register new formats or provide your own unpacker for any existing
    formats, by using :func:`register_unpack_format`.
diff --git a/Doc/library/sys.monitoring.rst b/Doc/library/sys.monitoring.rst
index 0674074b8c0..f62a4011e41 100644
--- a/Doc/library/sys.monitoring.rst
+++ b/Doc/library/sys.monitoring.rst
@@ -137,7 +137,8 @@ The following events are supported:
 
 .. monitoring-event:: PY_UNWIND
 
-   Exit from a Python function during exception unwinding.
+   Exit from a Python function during exception unwinding. This includes exceptions raised directly within the
+   function and that are allowed to continue to propagate.
 
 .. monitoring-event:: PY_YIELD
 
@@ -171,7 +172,7 @@ events, use the expression ``PY_RETURN | PY_START``.
       if get_events(DEBUGGER_ID) == NO_EVENTS:
           ...
 
-Events are divided into three groups:
+    Setting this event deactivates all events.
 
 .. _monitoring-event-local:
 
@@ -243,20 +244,23 @@ raise an exception unless it would be visible to other code.
 
 To allow tools to monitor for real exceptions without slowing down generators
 and coroutines, the :monitoring-event:`STOP_ITERATION` event is provided.
-:monitoring-event:`STOP_ITERATION` can be locally disabled, unlike :monitoring-event:`RAISE`.
+:monitoring-event:`STOP_ITERATION` can be locally disabled, unlike
+:monitoring-event:`RAISE`.
 
-Note that the :monitoring-event:`STOP_ITERATION` event and the :monitoring-event:`RAISE`
-event for a :exc:`StopIteration` exception are equivalent, and are treated as interchangeable
-when generating events. Implementations will favor :monitoring-event:`STOP_ITERATION` for
-performance reasons, but may generate a :monitoring-event:`RAISE` event with a :exc:`StopIteration`.
+Note that the :monitoring-event:`STOP_ITERATION` event and the
+:monitoring-event:`RAISE` event for a :exc:`StopIteration` exception are
+equivalent, and are treated as interchangeable when generating events.
+Implementations will favor :monitoring-event:`STOP_ITERATION` for performance
+reasons, but may generate a :monitoring-event:`RAISE` event with a
+:exc:`StopIteration`.
 
 Turning events on and off
 -------------------------
 
 In order to monitor an event, it must be turned on and a corresponding callback
-must be registered.
-Events can be turned on or off by setting the events either globally or
-for a particular code object.
+must be registered. Events can be turned on or off by setting the events either
+globally and/or for a particular code object. An event will trigger only once,
+even if it is turned on both globally and locally.
 
 
 Setting events globally
@@ -292,10 +296,6 @@ in Python (see :ref:`c-api-monitoring`).
    Activates all the local events for *code* which are set in *event_set*.
    Raises a :exc:`ValueError` if *tool_id* is not in use.
 
-Local events add to global events, but do not mask them.
-In other words, all global events will trigger for a code object,
-regardless of the local events.
-
 
 Disabling events
 ''''''''''''''''
@@ -325,8 +325,6 @@ except for a few breakpoints.
 Registering callback functions
 ------------------------------
 
-To register a callable for events call
-
 .. function:: register_callback(tool_id: int, event: int, func: Callable | None, /) -> Callable | None
 
    Registers the callable *func* for the *event* with the given *tool_id*
@@ -335,12 +333,16 @@ To register a callable for events call
    it is unregistered and returned.
    Otherwise :func:`register_callback` returns ``None``.
 
-
 Functions can be unregistered by calling
 ``sys.monitoring.register_callback(tool_id, event, None)``.
 
 Callback functions can be registered and unregistered at any time.
 
+Callbacks are called only once regardless if the event is turned on both
+globally and locally. As such, if an event could be turned on for both global
+and local events by your code then the callback needs to be written to handle
+either trigger.
+
 Registering or unregistering a callback function will generate a :func:`sys.audit` event.
 
 
@@ -353,37 +355,46 @@ Callback function arguments
    that there are no arguments to the call.
 
 When an active event occurs, the registered callback function is called.
+Callback functions returning an object other than :data:`DISABLE` will have no effect.
 Different events will provide the callback function with different arguments, as follows:
 
 * :monitoring-event:`PY_START` and :monitoring-event:`PY_RESUME`::
 
-    func(code: CodeType, instruction_offset: int) -> DISABLE | Any
+    func(code: CodeType, instruction_offset: int) -> object
 
 * :monitoring-event:`PY_RETURN` and :monitoring-event:`PY_YIELD`::
 
-    func(code: CodeType, instruction_offset: int, retval: object) -> DISABLE | Any
+    func(code: CodeType, instruction_offset: int, retval: object) -> object
 
-* :monitoring-event:`CALL`, :monitoring-event:`C_RAISE` and :monitoring-event:`C_RETURN`::
+* :monitoring-event:`CALL`, :monitoring-event:`C_RAISE` and :monitoring-event:`C_RETURN`
+  (*arg0* can be :data:`MISSING` specifically)::
 
-    func(code: CodeType, instruction_offset: int, callable: object, arg0: object | MISSING) -> DISABLE | Any
+    func(code: CodeType, instruction_offset: int, callable: object, arg0: object) -> object
 
+  *code* represents the code object where the call is being made, while
+  *callable* is the object that is about to be called (and thus
+  triggered the event).
   If there are no arguments, *arg0* is set to :data:`sys.monitoring.MISSING`.
 
+  For instance methods, *callable* will be the function object as found on the
+  class with *arg0* set to the instance (i.e. the ``self`` argument to the
+  method).
+
 * :monitoring-event:`RAISE`, :monitoring-event:`RERAISE`, :monitoring-event:`EXCEPTION_HANDLED`,
   :monitoring-event:`PY_UNWIND`, :monitoring-event:`PY_THROW` and :monitoring-event:`STOP_ITERATION`::
 
-    func(code: CodeType, instruction_offset: int, exception: BaseException) -> DISABLE | Any
+    func(code: CodeType, instruction_offset: int, exception: BaseException) -> object
 
 * :monitoring-event:`LINE`::
 
-    func(code: CodeType, line_number: int) -> DISABLE | Any
+    func(code: CodeType, line_number: int) -> object
 
 * :monitoring-event:`BRANCH_LEFT`, :monitoring-event:`BRANCH_RIGHT` and :monitoring-event:`JUMP`::
 
-    func(code: CodeType, instruction_offset: int, destination_offset: int) -> DISABLE | Any
+    func(code: CodeType, instruction_offset: int, destination_offset: int) -> object
 
   Note that the *destination_offset* is where the code will next execute.
 
 * :monitoring-event:`INSTRUCTION`::
 
-    func(code: CodeType, instruction_offset: int) -> DISABLE | Any
+    func(code: CodeType, instruction_offset: int) -> object
diff --git a/Doc/library/tarfile.rst b/Doc/library/tarfile.rst
index 7cec108a5bd..70466fbbc4d 100644
--- a/Doc/library/tarfile.rst
+++ b/Doc/library/tarfile.rst
@@ -18,8 +18,8 @@ higher-level functions in :ref:`shutil <archiving-operations>`.
 
 Some facts and figures:
 
-* reads and writes :mod:`gzip`, :mod:`bz2` and :mod:`lzma` compressed archives
-  if the respective modules are available.
+* reads and writes :mod:`gzip`, :mod:`bz2`, :mod:`compression.zstd`, and
+  :mod:`lzma` compressed archives if the respective modules are available.
 
 * read/write support for the POSIX.1-1988 (ustar) format.
 
@@ -47,6 +47,10 @@ Some facts and figures:
    or paths outside of the destination. Previously, the filter strategy
    was equivalent to :func:`fully_trusted <fully_trusted_filter>`.
 
+.. versionchanged:: 3.14
+
+   Added support for Zstandard compression using :mod:`compression.zstd`.
+
 .. function:: open(name=None, mode='r', fileobj=None, bufsize=10240, **kwargs)
 
    Return a :class:`TarFile` object for the pathname *name*. For detailed
@@ -71,6 +75,8 @@ Some facts and figures:
    +------------------+---------------------------------------------+
    | ``'r:xz'``       | Open for reading with lzma compression.     |
    +------------------+---------------------------------------------+
+   | ``'r:zst'``      | Open for reading with Zstandard compression.|
+   +------------------+---------------------------------------------+
    | ``'x'`` or       | Create a tarfile exclusively without        |
    | ``'x:'``         | compression.                                |
    |                  | Raise a :exc:`FileExistsError` exception    |
@@ -88,6 +94,10 @@ Some facts and figures:
    |                  | Raise a :exc:`FileExistsError` exception    |
    |                  | if it already exists.                       |
    +------------------+---------------------------------------------+
+   | ``'x:zst'``      | Create a tarfile with Zstandard compression.|
+   |                  | Raise a :exc:`FileExistsError` exception    |
+   |                  | if it already exists.                       |
+   +------------------+---------------------------------------------+
    | ``'a' or 'a:'``  | Open for appending with no compression. The |
    |                  | file is created if it does not exist.       |
    +------------------+---------------------------------------------+
@@ -99,6 +109,8 @@ Some facts and figures:
    +------------------+---------------------------------------------+
    | ``'w:xz'``       | Open for lzma compressed writing.           |
    +------------------+---------------------------------------------+
+   | ``'w:zst'``      | Open for Zstandard compressed writing.      |
+   +------------------+---------------------------------------------+
 
    Note that ``'a:gz'``, ``'a:bz2'`` or ``'a:xz'`` is not possible. If *mode*
    is not suitable to open a certain (compressed) file for reading,
@@ -115,6 +127,15 @@ Some facts and figures:
    For modes ``'w:xz'``, ``'x:xz'`` and ``'w|xz'``, :func:`tarfile.open` accepts the
    keyword argument *preset* to specify the compression level of the file.
 
+   For modes ``'w:zst'``, ``'x:zst'`` and ``'w|zst'``, :func:`tarfile.open`
+   accepts the keyword argument *level* to specify the compression level of
+   the file. The keyword argument *options* may also be passed, providing
+   advanced Zstandard compression parameters described by
+   :class:`~compression.zstd.CompressionParameter`. The keyword argument
+   *zstd_dict* can be passed to provide a :class:`~compression.zstd.ZstdDict`,
+   a Zstandard dictionary used to improve compression of smaller amounts of
+   data.
+
    For special purposes, there is a second format for *mode*:
    ``'filemode|[compression]'``.  :func:`tarfile.open` will return a :class:`TarFile`
    object that processes its data as a stream of blocks.  No random seeking will
@@ -146,6 +167,9 @@ Some facts and figures:
    | ``'r|xz'``  | Open an lzma compressed *stream* for       |
    |             | reading.                                   |
    +-------------+--------------------------------------------+
+   | ``'r|zst'`` | Open a Zstandard compressed *stream* for   |
+   |             | reading.                                   |
+   +-------------+--------------------------------------------+
    | ``'w|'``    | Open an uncompressed *stream* for writing. |
    +-------------+--------------------------------------------+
    | ``'w|gz'``  | Open a gzip compressed *stream* for        |
@@ -157,6 +181,9 @@ Some facts and figures:
    | ``'w|xz'``  | Open an lzma compressed *stream* for       |
    |             | writing.                                   |
    +-------------+--------------------------------------------+
+   | ``'w|zst'`` | Open a Zstandard compressed *stream* for   |
+   |             | writing.                                   |
+   +-------------+--------------------------------------------+
 
    .. versionchanged:: 3.5
       The ``'x'`` (exclusive creation) mode was added.
diff --git a/Doc/library/unittest.rst b/Doc/library/unittest.rst
index dcdda1719bf..d526e835caa 100644
--- a/Doc/library/unittest.rst
+++ b/Doc/library/unittest.rst
@@ -1131,7 +1131,7 @@ Test cases
       .. versionchanged:: 3.3
          Added the *msg* keyword argument when used as a context manager.
 
-   .. method:: assertLogs(logger=None, level=None)
+   .. method:: assertLogs(logger=None, level=None, formatter=None)
 
       A context manager to test that at least one message is logged on
       the *logger* or one of its children, with at least the given
@@ -1146,6 +1146,10 @@ Test cases
       its string equivalent (for example either ``"ERROR"`` or
       :const:`logging.ERROR`).  The default is :const:`logging.INFO`.
 
+      If given, *formatter* should be a :class:`logging.Formatter` object.
+      The default is a formatter with format string
+      ``"%(levelname)s:%(name)s:%(message)s"``
+
       The test passes if at least one message emitted inside the ``with``
       block matches the *logger* and *level* conditions, otherwise it fails.
 
@@ -1173,6 +1177,9 @@ Test cases
 
       .. versionadded:: 3.4
 
+      .. versionchanged:: next
+         Now accepts a *formatter* to control how messages are formatted.
+
    .. method:: assertNoLogs(logger=None, level=None)
 
       A context manager to test that no messages are logged on
diff --git a/Doc/library/zipfile.rst b/Doc/library/zipfile.rst
index 6a4fa67332e..bf9136a2139 100644
--- a/Doc/library/zipfile.rst
+++ b/Doc/library/zipfile.rst
@@ -129,14 +129,28 @@ The module defines the following items:
 
    .. versionadded:: 3.3
 
+.. data:: ZIP_ZSTANDARD
+
+   The numeric constant for Zstandard compression. This requires the
+   :mod:`compression.zstd` module.
+
    .. note::
 
-      The ZIP file format specification has included support for bzip2 compression
-      since 2001, and for LZMA compression since 2006. However, some tools
-      (including older Python releases) do not support these compression
-      methods, and may either refuse to process the ZIP file altogether,
-      or fail to extract individual files.
+      In APPNOTE 6.3.7, the method ID ``20`` was assigned to Zstandard
+      compression. This was changed in APPNOTE 6.3.8 to method ID ``93`` to
+      avoid conflicts, with method ID ``20`` being deprecated. For
+      compatibility, the :mod:`!zipfile` module reads both method IDs but will
+      only write data with method ID ``93``.
+
+   .. versionadded:: 3.14
+
+.. note::
 
+   The ZIP file format specification has included support for bzip2 compression
+   since 2001, for LZMA compression since 2006, and Zstandard compression since
+   2020. However, some tools (including older Python releases) do not support
+   these compression methods, and may either refuse to process the ZIP file
+   altogether, or fail to extract individual files.
 
 .. seealso::
 
@@ -176,10 +190,11 @@ ZipFile Objects
 
    *compression* is the ZIP compression method to use when writing the archive,
    and should be :const:`ZIP_STORED`, :const:`ZIP_DEFLATED`,
-   :const:`ZIP_BZIP2` or :const:`ZIP_LZMA`; unrecognized
-   values will cause :exc:`NotImplementedError` to be raised.  If
-   :const:`ZIP_DEFLATED`, :const:`ZIP_BZIP2` or :const:`ZIP_LZMA` is specified
-   but the corresponding module (:mod:`zlib`, :mod:`bz2` or :mod:`lzma`) is not
+   :const:`ZIP_BZIP2`, :const:`ZIP_LZMA`, or :const:`ZIP_ZSTANDARD`;
+   unrecognized values will cause :exc:`NotImplementedError` to be raised.  If
+   :const:`ZIP_DEFLATED`, :const:`ZIP_BZIP2`, :const:`ZIP_LZMA`, or
+   :const:`ZIP_ZSTANDARD` is specified but the corresponding module
+   (:mod:`zlib`, :mod:`bz2`, :mod:`lzma`, or :mod:`compression.zstd`) is not
    available, :exc:`RuntimeError` is raised. The default is :const:`ZIP_STORED`.
 
    If *allowZip64* is ``True`` (the default) zipfile will create ZIP files that
@@ -194,6 +209,10 @@ ZipFile Objects
    (see :class:`zlib <zlib.compressobj>` for more information).
    When using :const:`ZIP_BZIP2` integers ``1`` through ``9`` are accepted
    (see :class:`bz2 <bz2.BZ2File>` for more information).
+   When using :const:`ZIP_ZSTANDARD` integers ``-131072`` through ``22`` are
+   commonly accepted (see
+   :attr:`CompressionParameter.compression_level <compression.zstd.CompressionParameter.compression_level>`
+   for more on retrieving valid values and their meaning).
 
    The *strict_timestamps* argument, when set to ``False``, allows to
    zip files older than 1980-01-01 at the cost of setting the
@@ -415,9 +434,10 @@ ZipFile Objects
    read or append. *pwd* is the password used for encrypted files as a :class:`bytes`
    object and, if specified, overrides the default password set with :meth:`setpassword`.
    Calling :meth:`read` on a ZipFile that uses a compression method other than
-   :const:`ZIP_STORED`, :const:`ZIP_DEFLATED`, :const:`ZIP_BZIP2` or
-   :const:`ZIP_LZMA` will raise a :exc:`NotImplementedError`. An error will also
-   be raised if the corresponding compression module is not available.
+   :const:`ZIP_STORED`, :const:`ZIP_DEFLATED`, :const:`ZIP_BZIP2`,
+   :const:`ZIP_LZMA`, or :const:`ZIP_ZSTANDARD` will raise a
+   :exc:`NotImplementedError`. An error will also be raised if the
+   corresponding compression module is not available.
 
    .. versionchanged:: 3.6
       Calling :meth:`read` on a closed ZipFile will raise a :exc:`ValueError`.
diff --git a/Doc/using/configure.rst b/Doc/using/configure.rst
index df81a330549..a26d48d7d0a 100644
--- a/Doc/using/configure.rst
+++ b/Doc/using/configure.rst
@@ -29,6 +29,9 @@ Features and minimum versions required to build CPython:
 
 * Tcl/Tk 8.5.12 for the :mod:`tkinter` module.
 
+* `libmpdec <https://www.bytereef.org/mpdecimal/doc/libmpdec/>`_ 2.5.0
+  for the :mod:`decimal` module.
+
 * Autoconf 2.72 and aclocal 1.16.5 are required to regenerate the
   :file:`configure` script.
 
diff --git a/Doc/whatsnew/3.12.rst b/Doc/whatsnew/3.12.rst
index a65f59c0a72..7cfdc287b7f 100644
--- a/Doc/whatsnew/3.12.rst
+++ b/Doc/whatsnew/3.12.rst
@@ -2233,6 +2233,8 @@ Deprecated
 
 .. include:: ../deprecations/c-api-pending-removal-in-3.15.rst
 
+.. include:: ../deprecations/c-api-pending-removal-in-3.16.rst
+
 .. include:: ../deprecations/c-api-pending-removal-in-future.rst
 
 Removed
diff --git a/Doc/whatsnew/3.13.rst b/Doc/whatsnew/3.13.rst
index ef7c36d8539..0a3b3b30e01 100644
--- a/Doc/whatsnew/3.13.rst
+++ b/Doc/whatsnew/3.13.rst
@@ -2546,6 +2546,8 @@ Deprecated C APIs
 
 .. include:: ../deprecations/c-api-pending-removal-in-3.15.rst
 
+.. include:: ../deprecations/c-api-pending-removal-in-3.16.rst
+
 .. include:: ../deprecations/c-api-pending-removal-in-3.18.rst
 
 .. include:: ../deprecations/c-api-pending-removal-in-future.rst
@@ -2592,7 +2594,7 @@ Build Changes
 
 * The :file:`configure` option :option:`--with-system-libmpdec`
   now defaults to ``yes``.
-  The bundled copy of ``libmpdecimal`` will be removed in Python 3.15.
+  The bundled copy of ``libmpdec`` will be removed in Python 3.16.
 
 * Python built with :file:`configure` :option:`--with-trace-refs`
   (tracing references) is now ABI compatible with the Python release build
diff --git a/Doc/whatsnew/3.14.rst b/Doc/whatsnew/3.14.rst
index 8260f8ddc4e..c108a94692d 100644
--- a/Doc/whatsnew/3.14.rst
+++ b/Doc/whatsnew/3.14.rst
@@ -3053,6 +3053,8 @@ Deprecated
 
 .. include:: ../deprecations/c-api-pending-removal-in-3.15.rst
 
+.. include:: ../deprecations/c-api-pending-removal-in-3.16.rst
+
 .. include:: ../deprecations/c-api-pending-removal-in-3.18.rst
 
 .. include:: ../deprecations/c-api-pending-removal-in-future.rst
diff --git a/Doc/whatsnew/3.15.rst b/Doc/whatsnew/3.15.rst
index df636dc9051..706a816f888 100644
--- a/Doc/whatsnew/3.15.rst
+++ b/Doc/whatsnew/3.15.rst
@@ -291,6 +291,15 @@ typing
   (Contributed by Bénédikt Tran in :gh:`133823`.)
 
 
+unittest
+--------
+
+* Lets users specify formatter in TestCase.assertLogs.
+  :func:`unittest.TestCase.assertLogs` will now accept a formatter
+  to control how messages are formatted.
+  (Contributed by Garry Cairns in :gh:`134567`.)
+
+
 wave
 ----
 
@@ -346,6 +355,13 @@ Porting to Python 3.15
 
   (Contributed by Serhiy Storchaka in :gh:`133595`.)
 
+* Private functions promoted to public C APIs:
+
+  * ``PyMutex_IsLocked()`` : :c:func:`PyMutex_IsLocked`
+
+  The |pythoncapi_compat_project| can be used to get most of these new
+  functions on Python 3.14 and older.
+
 Deprecated C APIs
 -----------------