This addresses C extension build errors related to an undefined _hypot
symbol when building with the Microsoft Visual C++ Compiler for Python
2.7 [1] or MinGWPy [2]. It also addresses errors when building a C++
extension with MinGWPy and C++11 from cmath, 'error "::hypot' has not
been declared'

[1] https://www.microsoft.com/en-us/download/details.aspx?id=44266
[2] https://mingwpy.github.io/

(cherry picked from 0854b92c)

(cherry picked from commit 842acaab)

"dll" would leak if an error occurred in _validate_paramflags() or
GenericPyCData_new().
(cherry picked from commit d77d97c9)
Co-authored-by: Zackery Spytz <zspytz@gmail.com>

In _localemodule.c and selectmodule.c, remove dead code that would
cause double decrefs if run.

In addition, replace PyList_SetItem() with PyList_SET_ITEM() in cases
where a new list is populated and there is no possibility of an error.

In addition, check if the list changed size in the loop in array_array_fromlist().
(cherry picked from commit 99d56b53)
Co-authored-by: Zackery Spytz <zspytz@gmail.com>

Use "ll" instead of the nonstandard "q".
(cherry picked from commit 062cbb67)
Co-authored-by: Zackery Spytz <zspytz@gmail.com>

check_environ() of distutils.utils now catchs KeyError on calling
pwd.getpwuid(): don't create the HOME environment variable in this
case.

(cherry picked from commit 17d0c059)

bpo-34279, bpo-35412: support.run_unittest() no longer raises
TestDidNotRun if a test result contains skipped tests. The
exception is now only raised if no test have been run and no test
have been skipped.

(cherry picked from commit 3a8f4fef)

* bpo-16039: CVE-2013-1752: Change use of readline() in
  imaplib.IMAP4_SSL to limit line length. Remove IMAP4_SSL.readline()
  and IMAP4_SSL.read() to inherit safe IMAP4 implementation.
* bpo-20118: reenable test_linetoolong() of test_imaplib
  on ThreadedNetworkedTests and ThreadedNetworkedTestsSSL.
  The test now sets the _MAXLINE limit to 10 characters.

(cherry picked from commit cb342182)

(cherry picked from commit 7cf3d8e2)
Co-authored-by: Ned Deily <nad@python.org>

https://bugs.python.org/issue35401
(cherry picked from commit 419b5ffc2ca46d7adf0be6216ca3a6e40028e50f)
Co-authored-by: Ned Deily <nad@python.org>

Include <pyconfig.h> ealier in Modules/expat/xmlparse.c to define
properly _POSIX_C_SOURCE and _XOPEN_SOURCE.

Use GCC __attribute__((unused)) to mark the debug variable 'filename'
as unused in Python/ceval.c.

Include <pyconfig.h> ealier in Modules/expat/xmltok.c to define
properly _POSIX_C_SOURCE. Python defines _POSIX_C_SOURCE as 200809L,
whereas <features.h> (included indirectly by <string.h>) defines
_POSIX_C_SOURCE as 199506L.
(cherry picked from commit cf247359)
Co-authored-by: Victor Stinner <vstinner@redhat.com>

Fix xml.dom.minidom cloneNode() on a document with an entity: pass
the correct arguments to the user data handler of an entity (fix an
old copy/paste mistake).

Bug spotted and fix proposed by Charalampos Stratakis, initial
reproducer written by Petr Viktorin.
Co-Authored-By: Charalampos Stratakis <cstratak@redhat.com>
Co-Authored-By: Petr Viktorin <encukou@gmail.com>
(cherry picked from commit 8e041868)

(cherry picked from commit 42b1d612)
(cherry picked from commit 7a2cf1e7d3bf300e98c702589d405734f4a8fcf8)

(cherry picked from commit c9566b8c)
Co-authored-by: Andre Delfino <adelfino@gmail.com>

Define _CRT_SECURE_NO_WARNINGS in the Visual Studio pythoncore
project to make quiet security warnings when building zlib C files
(Modules\zlib\ subdirectory).

(cherry picked from commit 55f41e45)

Revert "[2.7] bpo-34172: multiprocessing.Pool leaks resources after being deleted (GH-9686)" (GH-10970)

This reverts commit 4a7dd30f.

Escape the \t and \n.
Follow up from https://github.com/python/cpython/pull/10814.
(cherry picked from commit 2d8f976c)
Co-authored-by: E Kawashima <e-kwsm@users.noreply.github.com>

[2.7] bpo-34052: Prevent SQLite functions from setting callbacks on exceptions. (GH-8113). (GH-10946) (GH-10955)

(cherry picked from commit 5b25f1d0)
(cherry picked from commit 1de91a0032fed500ddd3d8c4fb7a38c0b8719f67)

Co-authored-by: Sergey Fedoseev <fedoseev.sergey@gmail.com>.

(cherry picked from commit 67a93b3a)

(cherry picked from commit 4edeaeac)
Co-authored-by: Srinivas  Thatiparthy (శ్రీనివాస్  తాటిపర్తి) <thatiparthysreenivas@gmail.com>

(cherry picked from commit 1ce853f3)
Co-authored-by: Andre Delfino <adelfino@gmail.com>

* posixpath.expanduser() now returns the input path unchanged if
  the HOME environment variable is not set and pwd.getpwuid() raises
  KeyError (the current user identifier doesn't exist in the password
  database).
* Add test_no_home_directory() to test_site.

(cherry picked from commit f2f4555d)

When running test_bdb.py as a script, `import test_module` would be
importing the existing Lib/test/test_modules.py instead of the
tempcwd/test_module.py module which was dynamically created by
test_bdb.py itself.
(cherry picked from commit 54fd4550)
Co-authored-by: Alex H <1884912+lajarre@users.noreply.github.com>

On Travis CI, FTP tests of test_urllib2net randomly fail with "425
Security: Bad IP connecting".

test.pythoninfo now also logs TRAVIS environment variable.
(cherry picked from commit c11b3b19)
Co-authored-by: Victor Stinner <vstinner@redhat.com>

(cherry picked from commit 735abadd)
Co-Authored-By: Segev Finer <segev208@gmail.com>

They can be exposed when some C API calls fail due to lack of
memory.

* Failed Py_BuildValue() could cause an assertion error in the
  following TextIOWrapper.tell().
* initvalue could leak in StringIO.__getstate__() after failed
  PyDict_Copy().
(cherry picked from commit fdb5a50e)

Coarse benchmark on Fedora 29: 1.6 sec => 0.1 sec.
Co-Authored-By: Antoine Pitrou <solipsis@pitrou.net>

(cherry-picked from commit ba7c2260)

When Python is compiled in debug mode, PyMem_Malloc() uses debug
hooks, but it also uses pymalloc allocator instead of malloc().
Problem: pymalloc is not thread-safe, whereas PyMem_Malloc() is
thread-safe in release mode (it's a thin wrapper to malloc() in this
case).

Modify the debug hook to use malloc() for PyMem_Malloc().

(cherry picked from commit b7c21826)

Fix DeprecationWarning when tests are run using python -3.

The pthread implementation of PyThread_start_new_thread() now uses
malloc/free rather than PyMem_Malloc/PyMem_Free, since the latters
are not thread-safe.