testAccept() and testRecv() of test_socket.NonBlockingTCPTests have a
race condition: time.sleep() is used as a weak synchronization
primitive and the tests fail randomly on slow buildbots.

Use a reliable threading.Event to fix these tests.

Other changes:

* Replace send() with sendall()
* Add a timeout to select() in testAccept() and testRecv()
* Use addCleanup() to close sockets
* Use assertRaises()

(cherry picked from commit ebd5d6d6)

Running test_bytes with python -3 -Wd emits two DeprecationWarning on
"1/0". Use "1//0" to prevent the warning.

(cherry picked from commit a2e3585e)
Co-authored-by: Zackery Spytz <zspytz@gmail.com>

On Windows, test_env_changed() of test_regrtest is now skipped
because it fails  randomly for an unknown reason on "x86 Windows XP
VS9.0 2.7" buildbot worker.

Co-Authored-By: Pablo Galindo <Pablogsal@gmail.com>

Log TZ to debug a timezone issue... and a few more :-)

(cherry picked from commit 282c03d4)

(cherry picked from commit ba57963a)
Co-authored-by: takey <taketakeyyy@gmail.com>

https://bugs.python.org/issue35035

(cherry picked from commit 6b73bb52)
Co-authored-by: Julien Palard <julien@palard.fr>

Fixes assertion failures in _datetimemodule.c
introduced in the previous fix (see bpo-31752).

Rather of trying to handle an int subclass as exact int,
let it to use overridden special methods, but check the
result of divmod().
(cherry picked from commit 3ec0f495)
Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>

(cherry picked from commit 8b9c33ea)
Co-authored-by: Donald Stufft <donald@stufft.io>

This missed PyErr_NoMemory() could cause a SystemError when calling
_symtable.symtable().
(cherry picked from commit ad65f155)
Co-authored-by: Zackery Spytz <zspytz@gmail.com>

"single" needs to be decrefed if PyList_Append() fails.
(cherry picked from commit 4c596d54)
Co-authored-by: Zackery Spytz <zspytz@gmail.com>

Discovered using clang's MemorySanitizer.

A msan build will fail by simply executing: ./python -c 'u"\N"'
(cherry picked from commit 746b2d35)

Co-authored-by: Gregory P. Smith <greg@krypto.org> [Google LLC]

(cherry picked from commit 8e0b05e2)
Co-authored-by: Andrés Delfino <adelfino@gmail.com>

(cherry picked from commit 9404e773)
Co-authored-by: Andrés Delfino <adelfino@gmail.com>

https://bugs.python.org/issue33699
(cherry picked from commit b086c8af)



https://bugs.python.org/issue33699

This typo doesn't affect the result because wrong bits are discarded
on implicit conversion to unsigned char, but it trips UBSan
with -fsanitize=implicit-integer-truncation.
(cherry picked from commit 7a69cf47)
Co-authored-by: Alexey Izbyshev <izbyshev@ispras.ru>

(cherry picked from commit cdb96f45)
Co-authored-by: Andrés Delfino <adelfino@gmail.com>

(cherry picked from commit ae31e3fb)
Co-authored-by: Andrés Delfino <adelfino@gmail.com>

(cherry picked from commit c5eec442)
Co-authored-by: Andrés Delfino <adelfino@gmail.com>

(cherry picked from commit d6499103)
Co-authored-by: Andrés Delfino <adelfino@gmail.com>

The test depended on '/usr/share/zoneinfo/posixrules' or equivalent
because it set TZ without explicit DST transition rules. At least
on OpenSUSE Tumbleweed that file is linked to '/etc/localtime',
making the test fail with certain local timezones,
such as 'Europe/Moscow' which doesn't have DST transitions since 2011.
(cherry picked from commit f1b9ad3d)
Co-authored-by: Alexey Izbyshev <izbyshev@ispras.ru>

[2.7] bpo-35133: Fix mistakes when concatenate string literals on different lines. (GH-10284) (GH-10335) (GH-10336)

Two kind of mistakes:

1. Missed space. After concatenating there is no space between words.

2. Missed comma. Causes unintentional concatenating in a list of strings.
(cherry picked from commit 34fd4c20)
(cherry picked from commit 7054e5c80b6e98cd44e22d1bc2d7f0a94343089d)

(cherry picked from commit fe62d877)
Co-authored-by: İsmail Arılık <arilik.ismail@gmail.com>

[2.7] closes bpo-35139: The `pyexpat` module's macros in `Modules/Setup` now match `setup.py` (GH-10293)

This could cause compile errors on macOS or other platforms..
(cherry picked from commit 318ab63c)
Co-authored-by: Max Bélanger <aeromax@gmail.com>

_io.IncrementalNewlineDecoder's initializer possibly assigns out-of-range
value to the bitwise struct field.
(cherry picked from commit b08746bf)
Co-authored-by: Xiang Zhang <angwerzx@126.com>

Adding `max_num_fields` to `cgi.FieldStorage` to make DOS attacks harder by
limiting the number of `MiniFieldStorage` objects created by `FieldStorage`.

(cherry picked from commit 20914483)

(cherry picked from commit 53835e92)

(cherry picked from commit c0799ec9)
Co-authored-by: Gus Goulart <augusto@goulart.me>

(cherry picked from commit 18d57b4d)
Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>

Based on the investigation by Xiang Zhang.
(cherry picked from commit df13df41)

Referring to ``pytest`` as ``py.test`` is deprecated..
(cherry picked from commit d855f2fd)
Co-authored-by: Andreas Pelme <andreas@pelme.se>

Specify that blocks are non-overlapping. Change '!=' to '<'.
(cherry picked from commit d9bff4e8)
Co-authored-by: Terry Jan Reedy <tjreedy@udel.edu>

Prior to this revision, after the shutdown of a `BaseServer`,
the server accepted a last single request
if it was sent between the server socket polling
and the polling timeout.

This can be problematic for instance for a server restart
for which you do not want to interrupt the service,
by not closing the listening socket during the restart.
One request failed because of this behavior.

Note that only one request failed,
following requests were not accepted, as expected.

(cherry picked from commit 10cb3760)