* raise exception if _missing_ returns None or invalid type

(cherry picked from commit 0f14fc1a)
Co-authored-by: Andrés Delfino <adelfino@gmail.com>

(cherry picked from commit f192aeb9)
Co-authored-by: Srinivas  Thatiparthy (శ్రీనివాస్  తాటిపర్తి) <srinivasreddy@users.noreply.github.com>

On failure, _PyBytes_Resize() will deallocate the bytes object and set
"result" to NULL.

https://bugs.python.org/issue34824
(cherry picked from commit 365ad2ea)
Co-authored-by: Zackery Spytz <zspytz@gmail.com>

The xml.sax and xml.dom.domreg modules now obey
sys.flags.ignore_environment.
Signed-off-by: Christian Heimes <christian@python.org>

(cherry picked from commit 223e501f)
Co-authored-by: Christian Heimes <christian@python.org>

(cherry picked from commit d6a61f23)
Co-authored-by: Chris Barker <Chris.Barker@noaa.gov>

Address a C undefined behavior signed integer overflow issue in set object table resizing.  Our -fwrapv compiler flag and practical reasons why sets are unlikely to get this large should mean this was never an issue but it was incorrect code that generates code analysis warnings.
Co-authored-by: Sergey Fedoseev <fedoseev.sergey@gmail.com>

(cherry picked from commit acef6906)
Co-authored-by: Julien Palard <julien@palard.fr>

The docs in `library/unittest.mock` have been updated to remove
confusing terms about submock and be explicit about the behavior
expected.
(cherry picked from commit 96200eb2)
Co-authored-by: Mario Corchero <mariocj89@gmail.com>

The reprlib code was copied here instead of importing reprlib. I'm not sure if we really need to avoid the import, but since I expect dataclasses to be more common that reprlib, it seems wise. Plus, the code is small.
(cherry picked from commit dd13c88b)
Co-authored-by: Srinivas  Thatiparthy (శ్రీనివాస్  తాటిపర్తి) <srinivasreddy@users.noreply.github.com>

(cherry picked from commit 1deea5e5)

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)
Co-authored-by: matthewbelisle-wf <matthew.belisle@workiva.com>

(cherry picked from commit 68def052)
Co-authored-by: Zackery Spytz <zspytz@gmail.com>

(cherry picked from commit c984d20e)
Co-authored-by: Cheryl Sabella <cheryl.sabella@gmail.com>

According to the versionchanged note, the `strict` argument was removed in 3.3 and `policy` was added, but the name of the argument in the paragraph wasn't updated.
(cherry picked from commit a5ca9853)
Co-authored-by: Cheryl Sabella <cheryl.sabella@gmail.com>

(cherry picked from commit bbd90e4f)
Co-authored-by: Vinay Sajip <vinay_sajip@yahoo.co.uk>

C implementation of xml.etree.ElementTree.Element.__setstate__()
leaked references to children when called for already initialized
element.
(cherry picked from commit 6f906b3d)
Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>

 On macOS, fix reading from and writing into a file with a size larger than 2 GiB.
(cherry picked from commit 74a8b6ea)
Co-authored-by: Stéphane Wirtel <stephane@wirtel.be>

Restores the use of pyexpatns.h to isolate our embedded copy of the expat C
library so that its symbols do not conflict at link or dynamic loading time
with an embedding application or other extension modules with their own
version of libexpat.

https://github.com/python/cpython/commit/5dc3f23b5fb0b510926012cb3732dae63cddea60GH-diff-3afaf7274c90ce1b7405f75ad825f545 inadvertently removed it when upgrading expat.
(cherry picked from commit 9d4712bc)
Co-authored-by: Gregory P. Smith <greg@krypto.org>


https://bugs.python.org/issue35011

[3.7] [bpo-23420](https://bugs.python.org/issue23420): Verify the value of '-s' when execute the CLI of cProfile (GH-9925)

Verify the value for the parameter '-s' of the cProfile CLI. Patch by Robert
Kuska.
Co-authored-by: Robert Kuska <rkuska@gmail.com>
(cherry picked from commit fcd5e84a)





https://bugs.python.org/issue23420

(cherry picked from commit e385d066)
Co-authored-by: Stéphane Wirtel <stephane@wirtel.be>

Fix test_cmd_line_script.test_nonexisting_script(): the test must not
rely on sys.executable, since main.c uses config->program which can
be different than sys.executable in many cases (for example, on macOS
when using the framework).
(cherry picked from commit ea75187c)
Co-authored-by: Victor Stinner <vstinner@redhat.com>

bpo-23554: Change echo server example class name from EchoServerClientProtocol to EchoServerProtocol (GH-9859)

(cherry picked from commit 43a5bd7b)
Co-authored-by: Braden Groom <braden.groom@gmail.com>

python-gdb.py now handles errors on computing the line number
of a Python frame.

Changes:

* PyFrameObjectPtr.current_line_num() now catchs any Exception on
  calling addr2line(), instead of failing with a surprising "<class
  'TypeError'> 'FakeRepr' object is not subscriptable" error.
* All callers of current_line_num() now handle current_line_num()
  returning None.
* PyFrameObjectPtr.current_line() now also catchs IndexError on
  getting a line from the Python source file.
(cherry picked from commit 2e438cc2)
Co-authored-by: Victor Stinner <vstinner@redhat.com>

* Add News entry for the change in multiprocessing.reduction.recvfds
made in GH-9613.
(cherry picked from commit bd036d3d)
Co-authored-by: Pablo Galindo <Pablogsal@gmail.com>

Replace "Availability: xxx" with ".. availability:: xxx" in the doc.
 Original patch by Georg Brandl.
Co-Authored-By: Georg Brandl <georg@python.org>
 (cherry picked from commit 2d6097d0)
Co-authored-by: Cheryl Sabella <cheryl.sabella@gmail.com>

* fix dangling mention of key=str.lower in heapq doc

* Fix dangling mention of keyfunc example for sorted()
(cherry picked from commit 6bdb6f76)
Co-authored-by: Wolfgang Maier <wolfgang.maier@biologie.uni-freiburg.de>

bytes and bytearray constructors converted unexpected exceptions
(e.g. MemoryError and KeyboardInterrupt) to TypeError.
(cherry picked from commit e890421e)
Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>

(cherry picked from commit c8bb467f)
Co-authored-by: Andrés Delfino <adelfino@gmail.com>

Methods find(), findtext() and findall() of xml.etree.ElementTree.Element
were not able to find chldren which are instances of Element subclasses.
(cherry picked from commit b11c5667)
Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>

A Windows build with _tkinter, tkinter, and idlelib
but without ctypes is unlikely but apparently possible.
(cherry picked from commit d274afb5)
Co-authored-by: Terry Jan Reedy <tjreedy@udel.edu>

https://bugs.python.org/issue34970
(cherry picked from commit 97cf0828)
Co-authored-by: Andrew Svetlov <andrew.svetlov@gmail.com>

Covered all special cases: bytes, tuple, list, differend
kinds of iterables and iterators.
(cherry picked from commit 1a997eb2)
Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>

(cherry picked from commit d4d60134)
Co-authored-by: Zackery Spytz <zspytz@gmail.com>

For 3.7.1rc1 and 3.6.7rc1 we used a pre-release development
snapshot of Tk 8.6 to pick up some post-8.6.8 fixes for macOS.
But the snapshot introduced at least one regression (bpo-34927).
For rc2, revert to using the standard release 8.6.8 for now.
This reverts commit d9cfe5ed.

With macOS framework builds, test case test_nonexisting_script in
test_nonexisting_script fails because the test case assumes that
the file name in sys.executable will appear in the error message.
For macOS framework builds, sys.executable is the file name of the
stub launcher and its file name bears no relationship to the file
name of the actual python executable.  For now, skip the test in
this case.
(cherry picked from commit f6c29a65)
Co-authored-by: Ned Deily <nad@python.org>

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