[3.6] bpo-31416: Fix assertion failures in case of a bad warnings.filters or warnings.defaultaction. (GH-3496) (#3509)

Patch by Oren Milman..
(cherry picked from commit 9d984fd2)

This undoes a853a8ba except for the pytime.c
parts. We want to continue to allow IEEE 754 doubles larger than FLT_MAX to be
rounded into finite floats. Tests were added to very this behavior.
(cherry picked from commit 2bb69a5b)

(cherry picked from commit 8239fd70)

Adding to an int entry is not the same as deleting and inserting
because int('') will fail.
(cherry picked from commit 667522ef)

[3.6] bpo-31411: Prevent raising a SystemError in case warnings.onceregistry is not a dictionary. (GH-3485). (#3494)

(cherry picked from commit 252033d5)

(cherry picked from commit 2e6bb448)

This fixes an omission in the ttk conversion patch for this issue, hence no new news.
Patch by Cheryl Sabella.
(cherry picked from commit 3866d9bb)

About 10 IDLE features were implemented as supposedly optional
extensions.  Their different behavior could be confusing or worse for
users and not good for maintenance.  Hence the conversion.

The main difference for users is that user configurable key bindings
for builtin features are now handled uniformly.  Now, editing a binding
in a keyset only affects its value in the keyset.  All bindings are
defined together in the system-specific default keysets in config-
extensions.def.  All custom keysets are saved as a whole in config-
extension.cfg.  All take effect as soon as one clicks Apply or Ok.

The affected events are '<<force-open-completions>>', '<<expand-word>>',
'<<force-open-calltip>>', '<<flash-paren>>', '<<format-paragraph>>',
'<<run-module>>', '<<check-module>>', and '<<zoom-height>>'.  Any
(global) customizations made before 3.6.3 will not affect their keyset-
specific customization after 3.6.3. and vice versa.

Inital patch by Charles Wohlganger, revised by Terry Jan Reedy.
(cherry picked from commit 58fc71c4)

Thanks Arfrever!
Signed-off-by: Christian Heimes <christian@python.org>

(cherry picked from commit 3cedf46c)

getstate and setstate are instance methods, same as encode and reset.
(cherry picked from commit 30644dee)

Patch by Paul.j3.  Includes an unrelated but useful addition to the
optparse porting section.
(cherry picked from commit 0c7983e4)

(cherry picked from commit a7fbad96)

* bpo-31392: Improve SSL error handling on Windows

* Remove unnecessary Windows mention in NEWS.
(cherry picked from commit e6eb48c1)

* Modify NaN check function and error message
* Fix pytime.c when arg is nan
* fix whitespace
(cherry picked from commit 829dacce)

(cherry picked from commit 34b54873)

(cherry picked from commit af8d6b90)

(cherry picked from commit e3b2b4b8)

* bpo-29136: Add TLS 1.3 support

TLS 1.3 introduces a new, distinct set of cipher suites. The TLS 1.3
cipher suites don't overlap with cipher suites from TLS 1.2 and earlier.
Since Python sets its own set of permitted ciphers, TLS 1.3 handshake
will fail as soon as OpenSSL 1.1.1 is released. Let's enable the common
AES-GCM and ChaCha20 suites.

Additionally the flag OP_NO_TLSv1_3 is added. It defaults to 0 (no op) with
OpenSSL prior to 1.1.1. This allows applications to opt-out from TLS 1.3
now.

Signed-off-by: Christian Heimes <christian@python.org>.
(cherry picked from commit cb5b68ab)

[3.6] bpo-30640: Fix undefined behavior in _PyFunction_FastCallDict() and PyEval_EvalCodeEx() (GH-2919) (#2964)

k + 1 was calculated with k = NULL..
(cherry picked from commit c6ea8974)

Rather than requiring the path to blurb and/or sphinx-build to be specified to the make rule, enhance the Doc/Makefile to look for each first in a virtual environment created by make venv and, if not found, look on the normal process PATH. This allows the Doc/Makefile to take advantage of an installed spinx-build or blurb and, thus, do the right thing most of the time. Also, make the directory for the venv be configurable and document the `make venv` target.
(cherry picked from commit 590665c3)

* bpo-27340: Use memoryview in SSLSocket.sendall()

SSLSocket.sendall() now uses memoryview to create slices of data. This fix
support for all bytes-like object. It is also more efficient and avoids
costly copies.
Signed-off-by: Christian Heimes <christian@python.org>

* Cast view to bytes, fix typo

Signed-off-by: Christian Heimes <christian@python.org>.
(cherry picked from commit 888bbdc1)

Signed-off-by: Christian Heimes <christian@python.org>
(cherry picked from commit 17c9ac92)

To match the documentation updates already made.
Also renames the local variable used within to match
what it actually holds.
(cherry picked from commit 2eb0cb47)

* Fix ZeroMQSocketListener and ZeroMQSocketHandler examples

* Use send_json and recv_json to simplify pyzmq interfacing

* Add News entry
(cherry picked from commit 586c0502)

Also provide a solution if the user wants to keep multiple blank lines.
(cherry picked from commit 397c467c)

(cherry picked from commit a853a8ba)

Use base class rather than metaclass in examples.
(cherry picked from commit 122e88a8)

Signed-off-by: Christian Heimes <christian@python.org>
(cherry picked from commit d3b9f97e)

The `subprocess.getstatusoutput` API was inadvertently changed
in Python 3.3.4.  Document the change, it is too late to undo the
API change now as it has shipped in many stable releases.
(cherry picked from commit 738b7d97)

For f-string ast nodes, fix the line and columns so that tools such as flake8 can identify them correctly.
(cherry picked from commit e7c566ca)

(cherry picked from commit 1ba9469e)

Signed-off-by: Christian Heimes <christian@python.org>
(cherry picked from commit ad0ffa03)

(cherry picked from commit 8204b903)

[3.6] bpo-31340: Change to building with MSVC v141 (included with Visual Studio 2017) (GH-3311) (#3386)