Frame's field f_tstate is NULL when the generator is exhausted.

(cherry picked from commit 4505f65a)
Co-authored-by: Gus Goulart <augusto@goulart.me>

When Python is built with the intel control-flow protection flags,
-mcet -fcf-protection, gdb is not able to read the stack without
actually jumping inside the function. This means an extra
'next' command is required to make the $pc (program counter)
enter the function and make the stack of the function exposed to gdb.

test_gdb: get_gdb_repr() now uses the "backtrace 1" command after
breakpoint, as in the master branch.
Co-Authored-By: Marcel Plch <gmarcel.plch@gmail.com>

(cherry picked from commit 9b7c74ca)
(cherry picked from commit 79d21331)

Fix a reference issue inside multiprocessing.Pool that caused the pool to remain alive if it was deleted without being closed or terminated explicitly.

* bpo-13407: Mention that tarfile doesn't support multistream bzip2 files

* Add mention to bz2 module also

Fix the following warning:

Python/pystrtod.c: In function 'format_float_short':
Python/pystrtod.c:1007:13: warning: 'strncpy' output truncated before terminating nul copying 3 bytes from a string of the same length [-Wstringop-truncation]
             strncpy(p, "ERR", 3);

(cherry picked from commit 9fb84157)

(cherry picked from commit e0e5065d)
Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>

This makes streamed zips compatible with MacOS Archive Utility and
other applications.
(cherry picked from commit 4ba3b50b)
Co-authored-by: Silas Sewell <silas@sewell.org>

Also make docs for NEWFALSE and NEWTRUE more consistent
with docs for other opcodes.
(cherry picked from commit 488cfb78)
Co-authored-by: Krzysztof Wroblewski <krzysiek.wr@gmail.com>

https://bugs.python.org/issue34623
(cherry picked from commit 026337a7)
Co-authored-by: Christian Heimes <christian@python.org>


https://bugs.python.org/issue34623

(cherry picked from commit 8213eadd)
Co-authored-by: Berker Peksag <berker.peksag@gmail.com>

Update all test certs and keys to use future proof crypto settings:

* 3072 bit RSA keys
* SHA-256 signature

Signed-off-by: Christian Heimes <christian@python.org>.
(cherry picked from commit e6dac007)



https://bugs.python.org/issue34542

Co-authored-by: Vladimir Matveev <v2matveev@outlook.com>

(cherry picked from commit 9bdb7be4)

The C accelerated _elementtree module now initializes hash randomization
salt from _Py_HashSecret instead of libexpat's default CPRNG.
Signed-off-by: Christian Heimes <christian@python.org>

https://bugs.python.org/issue34623.
(cherry picked from commit cb5778f0)
Co-authored-by: Christian Heimes <christian@python.org>



https://bugs.python.org/issue34623

Include ``openssl/dh.h`` header file to fix implicit function declaration of ``DH_free()``.

Signed-off-by: Alexandru Ardelean <ardeleanalex@gmail.com>.
(cherry picked from commit b3a271fc)
Co-authored-by: Alexandru Ardelean <ardeleanalex@gmail.com>



https://bugs.python.org/issue34710

(cherry picked from commit 76aa2c0a9a8dd3ac90b91e7342c8ce8125bf21f9)
Co-authored-by: larryhastings <larry@hastings.org>

(cherry picked from commit 3fe33043)



https://bugs.python.org/issue19417

When the server has closed the connection before sending a status-line,
the client's error message should have a more descriptive error message

https://bugs.python.org/issue8450


https://bugs.python.org/issue8450

(cherry picked from commit a4414ef2)

It was accidentally added in 107f3cc7.

(cherry picked from commit a710ebd2)

(cherry picked from commit 40caa05f)
Co-authored-by: Benjamin Peterson <benjamin@python.org>

Reported by Svace static analyzer.
(cherry picked from commit 6f82bffd)
Co-authored-by: Alexey Izbyshev <izbyshev@ispras.ru>

It was backported in 0cc43df0.

(cherry picked from commit b9bf9d02)
Co-authored-by: Benjamin Peterson <benjamin@python.org>

https://bugs.python.org/issue34405

(cherry picked from commit 31912b43c903aafad09350899ed6a9dec7c43421)
Co-authored-by: Ned Deily <nad@python.org>

<!-- issue-number: [bpo-34405](https://www.bugs.python.org/issue34405) -->
https://bugs.python.org/issue34405
<!-- /issue-number -->

(cherry picked from commit 6b273f7f)
Co-authored-by: Bo Bayles <bbayles@gmail.com>

[2.7] closes bpo-31608: Fix a crash in methods of a subclass of _collections.deque with a bad __new__(). (GH-9179)

(cherry picked from commit 5033aa77)
Co-authored-by: Benjamin Peterson <benjamin@python.org>

Python 2 never checked for I/O error when reading .py files and
thus could mistake an I/O error for EOF and create incorrect .pyc
files.
This adds an check for this and aborts on an error.

Many type object initializations labeled a field "tp_size" in the
comment, but the name of that field is tp_basicsize..
(cherry picked from commit 0e0bc4e2)
Co-authored-by: Peter Eisentraut <peter@eisentraut.org>

(cherry picked from commit 4e519377)
Co-authored-by: Zackery Spytz <zspytz@gmail.com>

When calling tp_descr_get(self, obj, type), make sure that
we own a strong reference to "self".

(cherry picked from commit 8f735485)

(cherry picked from commit 7d81e8f5)
Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>

distutils.spawn.find_executable() now falls back on os.defpath if the
PATH environment variable is not set.

(cherry picked from commit 39487196)

The change to Tools/scripts/diff.py effectively backports part of
a2637729.
The test code changed in Doc/library/difflib.rst is not present in current 3.x.

... by removing a superfluous "either".

Reported by Никита Люшненко on docs@

(cherry picked from commit 98b976a2)