Skip tests with test.support.import_module('multiprocessing.synchronize')
instead when the semaphore implementation is broken or missing.

The current behaviour of yield expressions inside comprehensions  and
generator expressions is essentially an accident of implementation - it
arises implicitly from the way the compiler handles yield expressions inside
nested functions and generators.

Since the current behaviour wasn't deliberately designed, and is inherently
confusing, we're deprecating it, with no current plans to reintroduce it.
Instead, our advice will be to use a named nested generator definition
for cases where this behaviour is desired.

In _io_FileIO_readall_impl(), lseek() and _Py_fstat_noraise() were called
without releasing the GIL. This can cause all threads to hang for
unlimited time when calling FileIO.read() and the NFS server is not
accessible.

Fix the following false-alarm Coverity warning:

    Result is not floating-point
    (UNINTENDED_INTEGER_DIVISION)integer_division: Dividing integer
    expressions 9223372036854775807LL and 1000LL, and then converting
    the integer quotient to type double. Any remainder, or fractional
    part of the quotient, is ignored.

    To compute and use a non-integer quotient, change or cast either
    operand to type double. If integer division is intended, consider
    indicating that by casting the result to type long long .

Avoid also "cd $(srcdir)" to not change the current directory.

* Fixed saving bytearrays.
* Identical objects will be saved only once.
* Equal references will be load as identical objects.
* Added support for saving and loading recursive data structures.

When PyGILState_Ensure() is called in a non-Python thread before
PyEval_InitThreads(), only call PyEval_InitThreads() after calling
PyThreadState_New() to fix a crash.

Add an unit test in test_embed.

with the persistent_id() and persistent_load() methods.

_Py_InitializeEx_Private() now calls
_PyMainInterpreterConfig_ReadEnv() to read environment variables
PYTHONHOME and PYTHONPATH, and set the program name.

Handle PyModule_AddIntConstant() and PyModule_AddStringConstant()
failures. Add also constants before calling setup_readline(), since
setup_readline() registers callbacks which uses a reference to the
module, whereas the module is destroyed if adding constants fails.

Fix Coverity warning:

CID 1414686: Unchecked return value (CHECKED_RETURN)
2. check_return: Calling PyModule_AddStringConstant without checking
return value (as is done elsewhere 45 out of 55 times).

bpo-31705.

* bpo-32101: Add sys.flags.dev_mode flag
  Rename also the "Developer mode" to the "Development mode".
* bpo-32101: Add PYTHONDEVMODE environment variable
  Mention it in the development chapiter.

* Add most_recent_first parameter to tracemalloc.Traceback.format to allow
   reversing the order of the frames in the output
* Reversed default sorting of tracemalloc.Traceback frames
* Allowed negative limit, truncating from the other side.

Partially revert the commit fe2d5bab.
Clarify the usage of this file in Misc/README.

* Drop Python 3.4 code from asyncio

* Fix notes

* Add missing imports

* Restore comment

* Resort imports

* Drop Python 3.4-3.5 specific code

* Drop redunant check

* Fix tests

* Restore _COROUTINE_TYPES order

* Remove useless code

* Fix _PyMem_SetupAllocators("debug"): always restore allocators to
  the defaults, rather than only caling _PyMem_SetupDebugHooks().
* Add _PyMem_SetDefaultAllocator() helper to set the "default"
  allocator.
* Add _PyMem_GetAllocatorsName(): get the name of the allocators
* main() now uses debug hooks on memory allocators if Py_DEBUG is
  defined, rather than calling directly malloc()
* Document default memory allocators in C API documentation
* _Py_InitializeCore() now fails with a fatal user error if
  PYTHONMALLOC value is an unknown memory allocator, instead of
  failing with a fatal internal error.
* Add new tests on the PYTHONMALLOC environment variable
* Add support.with_pymalloc()
* Add the _testcapi.WITH_PYMALLOC constant and expose it as
   support.with_pymalloc().
* sysconfig.get_config_var('WITH_PYMALLOC') doesn't work on Windows, so
   replace it with support.with_pymalloc().
* pythoninfo: add _testcapi collector for pymem

Remove the test.support.requires_android_level decorator.

characters/bytes for non-negative n.  This makes it compatible with
read() methods of other file-like objects.

``uuid.getnode()`` now preferentially returns universally administered MAC addresses if available, over locally administered MAC addresses.  This makes a better guarantee for global uniqueness of UUIDs returned from ``uuid.uuid1()``.  If only locally administered MAC addresses are available, the first such one found is returned.

Also improve internal code style by being explicit about ``return None`` rather than falling off the end of the function.

Improve the test robustness.

Revert distutils changes of the commit
696b501c and remove the realm
variable.

CPython migrated from CVS to Subversion, to Mercurial, and then to
Git. CVS and Subversion are not more used to develop CPython.

* platform module: drop support for sys.subversion. The
  sys.subversion attribute has been removed in Python 3.3.
* Remove Misc/svnmap.txt
* Remove Tools/scripts/svneol.py
* Remove Tools/scripts/treesync.py

* bpo-32071: Fix an undocumented behaviour regression

* bpo-32071: Add 3.7 release note entry for unittest -k

* distutils.config: Use the PyPIRCCommand.realm attribute if set
* turtledemo: wait until macOS osascript command completes to not
  create a zombie process
* Tools/scripts/treesync.py: declare 'default_answer' and
  'create_files' as globals to modify them with the command line
  arguments. Previously, -y, -n, -f and -a options had no effect.

flake8 warning: "F841 local variable 'p' is assigned to but never
used".

* Remove asyncio.selectors and asyncio._overlapped symbols from the
  namespace of the asyncio module
* Replace "from asyncio import selectors" with "import selectors"
* Replace "from asyncio import _overlapped" with "import _overlapped"

asyncio.selectors was added to support Python 3.3, which doesn't have
selectors in its standard library, and Python 3.4 in the same code
base. Same rationale for asyncio._overlapped. Python 3.3 reached its
end of life, and asyncio is no more maintained as a third party
module on PyPI.

The asyncio/compat.py file was written to support Python < 3.5 and
Python < 3.5.2. But Python 3.5 doesn't accept bugfixes anymore, only
security fixes. There is no more need to backport bugfixes to Python
3.5, and so no need to have a single code base for Python 3.5, 3.6
and 3.7.

Say hello (again) to "async" and "await", who became real keywords in
Python 3.7 ;-)

Since Python 3.5, socket.socketpair() is also available on Windows,
and so can be used directly, rather than using
asyncio.windows_utils.socketpair().

Currently, two tests fail with PYTHONASYNCIODEBUG=1 (or using -X
dev).

It was only used on Python 3.3, now only Future._log_traceback is
used.