Prevent passing other invalid environment variables and command arguments.

Patch by Cheryl Sabella

Fix a regression introduced by myself in the commit
526b2265.

* bpo-30726: Fix elementtree warnings on Windows

Caused by usage of `getenv` which should be safe. And a few integer
truncations which should also be ok.

* bpo-30726: Don't ignore libexpat warnings which haypo intends to fix upstream

bpo-30726, bpo-29591: libexpat 2.2.1 of Modules/expat/ now uses
a winconfig.h configuration file which already defines:

* XML_NS
* XML_DTD
* BYTEORDER=1234
* XML_CONTEXT_BYTES=1024
* HAVE_MEMMOVE

Remove these defines from PCbuild/_elementtree.vcxproj to prevent
compiler warnings.
Co-Authored-By: Jeremy Kloth <jeremy.kloth@gmail.com>

Straightforward. While we're at it, though, strip trailing whitespace from generated tables.

Add "Misc/NEWS.d" directory tree for "blurb".

CPython workflow is changing!  We're going to start using "blurb"
to manage Misc/NEWS entries:
    https://github.com/python/core-workflow
(This will be a big win for release managers, honest.)

This checkin simply populates the "Misc/NEWS.d" subdirectory tree
so that people can start putting their news entries in there.
No other changes (yet).

When a class and its subclass are present, the latter is skipped.

bpo-29212: Fix the ugly ThreadPoolExecutor thread name.

Fixes the newly introduced ugly default thread name for concurrent.futures
thread.ThreadPoolExecutor threads.  They'll now resemble the old <=3.5
threading default Thread-x names by being named ThreadPoolExecutor-y_n.

bpo-30604: port fix from 3.6 dropping binary compatibility tweaks

* bpo-30183: Fixes HP-UX cc compilation error in pytime.c

HP-UX does not support the CLOCK_MONOTONIC identifier, and will fail to
compile:

    "Python/pytime.c", line 723: error #2020: identifier
    "CLOCK_MONOTONIC" is undefined
          const clockid_t clk_id = CLOCK_MONOTONIC;

Add a new section for __hpux that calls 'gethrtime()' instead of
'clock_gettime()'.

* bpo-30183: Removes unnecessary return

* bpo-30616: Functional API of enum allows to create empty enums.

* Update NEWS

move addition to avoid conflict

New file: Modules/expat/siphash.h.

Comceptually -> Conceptually

Improve the description of the high and low parameters for set_write_buffer_limits.
Also fixed a small grammatical issue.

* Make PyTraceMalloc_Track() and PyTraceMalloc_Untrack() functions
  public (remove the "_" prefix)
* Remove the _PyTraceMalloc_domain_t type: use directly unsigned
  int.
* Document methods

Note: methods are already tested in test_tracemalloc.

They now always return bytes.

Updated the gettext documentation.

splithost() expects an URL starting with "//" not with "http://".

The current regex based splitting produces a wrong result. For example::

  http://abc#@def

Web browsers parse that URL as ``http://abc/#@def``, that is, the host
is ``abc``, the path is ``/``, and the fragment is ``#@def``.

* Fixes build scripts to find msbuild.exe and stop relying on vcvarsall.bat
Also fixes bdist_wininst.vcxproj to use correct version in generated name.

- removes PY_WARN_ON_C_LOCALE build time flag
- locale coercion and compatibility warnings are now always compiled
  in, but are off by default
- adds PYTHONCOERCECLOCALE=warn runtime option to aid in
  debugging potentially locale related compatibility problems

Due to not-yet-resolved test failures on *BSD systems (including
Mac OS X), this also temporarily disables UTF-8 as a locale coercion
target, and skips testing the interpreter's behavior in the POSIX locale.

elem is the result of .lower() 6 lines above the handle_endtag call.
Patch by Motoki Naruse

This reverts commit 258bfc46.

* bpo-30523: Add --list-cases unittest

* Addressed haypo's request

* Addressed haypo's request

This caused a segfault on eval("f'\\\n'") and eval("f'\\\r'") in debug build.

* bpo-30523: regrtest: Add --list-cases option

* bpo-30523: Enhance --list-cases

* Add get_abs_module() function, use it in list_cases()
* list_cases() now logs skipped tests into stderr

* Remove unused doctest