(cherry picked from commit efb560ee)

This was possible before.  GH-1560 introduced a regression after 3.6.2 got
released where only sequences were accepted now.  This commit addresses this
problem.
(cherry picked from commit 574562c5)

Use prefixed macro names for the `authoraddress` function, add T2A to the font encoding in LaTeX sources to support Cyrillic characters in the PDF documentation, and replace the deprecated `font_size` config option with `pointsize`.
(cherry picked from commit da9b4cfb)

* bpo-31499, xml.etree: Fix xmlparser_gc_clear() crash

xml.etree: xmlparser_gc_clear() now sets self.parser to NULL to prevent a
crash in xmlparser_dealloc() if xmlparser_gc_clear() was called previously
by the garbage collector, because the parser was part of a reference cycle.
Co-Authored-By: Serhiy Storchaka <storchaka@gmail.com>
(cherry picked from commit e727d41f)

(cherry picked from commit 55679e0e)

This reverses a never-released regression resulting from bpo-31287.
(cherry picked from commit 0efc7c67)

Shorten the comment to: "using integer format specifier"
(cherry picked from commit 63c591c0)

Canceling timers prevents a warning message when test_idle completes.
(This is the minimum fix needed before upcoming releases.)
(cherry picked from commit a6bb313c)

Provide additional examples of using format specifiers in f-strings
Added examples for using integer and date format specifiers.
(cherry picked from commit f3618970)

(cherry picked from commit 0ec8c4bd)

(cherry picked from commit da67e0d6)

When apply ConfigDialog changes, call .reload on each class with non-key options.
Change ParenMatch so that updates affect current instances.
(cherry picked from commit 5777ecc4)

* bpo-31234: Join threads in tests (#3572)

Call thread.join() on threads to prevent the "dangling threads"
warning.

(cherry picked from commit 18e95b41)

* bpo-31234: Join threads in test_hashlib (#3573)

* bpo-31234: Join threads in test_hashlib

Use thread.join() to wait until the parallel hash tasks complete
rather than using events. Calling thread.join() prevent "dangling
thread" warnings.

* test_hashlib: minor PEP 8 coding style fixes

(cherry picked from commit 8dcf22f4)

* bpo-31234: Join threads in test_threading (#3579)

Call thread.join() to prevent the "dangling thread" warning.

(cherry picked from commit b8c7be2c)

* bpo-31234: Join threads in test_queue (#3586)

Call thread.join() to prevent the "dangling thread" warning.

(cherry picked from commit 167cbde5)

* bpo-31234: Join timers in test_threading (#3598)

Call the .join() method of threading.Timer timers to prevent the
"threading_cleanup() failed to cleanup 1 threads" warning.

(cherry picked from commit da3e5cf9)

'Strip trailing whitespace' is not limited to spaces.  Wording caters to beginners who
do know know the meaning of 'whitespace'.  Multiline string literals are not skipped.
(cherry picked from commit ff702890)

Reproduction of Idlelib changes in Serhiy's 3.7 patch.

Enabled by default was a temporary expedient.  The fix is to add a user override to enable.
(cherry picked from commit d384a81f)

* Avoid calling "PyObject_GetAttrString()" (and potentially executing user code) with a live exception set.

* Ignore only AttributeError on attribute lookups in ElementTree.XMLParser() and propagate all other exceptions.
(cherry picked from commit c8d8e15b)

This makes the default behavior (without specifying `globalns` manually) more
predictable for users, finds the right globalns automatically.

Implementation for classes assumes has a `__module__` attribute and that module
is present in `sys.modules`.  It does this recursively for all bases in the
MRO.  For modules, the implementation just uses their `__dict__` directly.

This is backwards compatible, will just raise fewer exceptions in naive user
code.

Originally implemented and reviewed at https://github.com/python/typing/pull/470.
(cherry picked from commit f350a268)

[3.6] bpo-31471: Fix assertion failure in subprocess.Popen() on Windows, in case env has a bad keys() method. (GH-3580) (#3584)

(cherry picked from commit 0b3a87ef)

Some of the proxied methods use internal Logger state which isn't proxied,
causing failures if an adapter is applied to another adapter.

This commit fixes the issue, adds a new test for the use case.
(cherry picked from commit 1bbd482b)

The `blake2b` function does not take the `data` keyword argument.
The hex digest returned by sign was a string, whereas compare_digest expects bytes-like objects.
Typo fix: compare_digesty -> compare_digest
(cherry picked from commit 312ffead)

Cast Py_buffer.len (Py_ssize_t, signed) to size_t (unsigned) to
prevent the following warning:

Modules/_ssl.c:3089:21: warning: comparison between signed and
unsigned integer expressions [-Wsign-compare].
(cherry picked from commit 5a61559f)

[3.6] bpo-31418: Fix an assertion failure in PyErr_WriteUnraisable() in case of an exception with a bad __module__ attribute. (GH-3539) (#3556)

(cherry picked from commit f6e61df0)

Update the link from Misc/NEWS to Misc/NEWS.d
(cherry picked from commit 1b8f612e)

* Copy changes to typing from upstream repo
* Add NEWS entry
(cherry picked from commit 65bc6205)

* bpo-31234: Fix dangling thread in test_ftp/poplib (#3540)

Explicitly clear the server attribute in test_ftplib and test_poplib
to prevent dangling thread.

(cherry picked from commit d403a29c)

* bpo-31234: Fix dangling thread in test_ftplib (#3544)

Clear also self.server_thread attribute in TestTimeouts.tearDown().

(cherry picked from commit b157ce1e)

(cherry picked from commit acb9fa79)

Call POP3.close(), don't close close directly the sock attribute.
(cherry picked from commit d165e14e)

(cherry picked from commit 830d7d29)

* Don't leak the module into sys.modules
* Avoid dangling thread
(cherry picked from commit 41bbd82b)

Store exceptions as string rather than object to prevent reference
cycles which cause leaking dangling threads.
(cherry picked from commit 86871015)

(cherry picked from commit b8d1b9d7)