Co-authored-by: Jake Davis <jcdavis@awedge.net>.
(cherry picked from commit 2411292b)

Use `f` as the name of the first parameter of `csv.DictReader` and
`csv.DictWriter` classes.

strop is highly legacy and can be safely compiled out in most installations. Let's not fail the test suite for its absence.

Manual backport of GH-5485

Clarify that the level argument is used to determine whether to
perform absolute or relative imports: 0 is absolute, while a positive number
is the number of parent directories to search relative to the current module..
(cherry picked from commit 461d225b)
Co-authored-by: oldk <oldk1331@users.noreply.github.com>

instead of crashing due to a stack overflow.

This perhaps will fix similar problems in other extension types.
(cherry picked from commit 1fb72d2a)

_test_multiprocessing.test_queue_feeder_donot_stop_onexc() now uses a
timeout of 1 second on Queue.get(), instead of 0.1 second, for slow
buildbots.

(cherry picked from commit 8f6eeaf2)

Patch by Bo Bayles.

It will be triggered when propagating an exception.
(cherry picked from commit 79db11ce)

(cherry picked from commit 9ed0aee2)

The nismodule is now compatible with new libnsl and headers location

Signed-off-by: Christian Heimes <christian@python.org>.
(cherry picked from commit 29a7df78)

In str.join, if any of the iterable contains a Unicode object,
str.join will return a Unicode object.

A Type error will be raised if iterable contains values other
than a string or Unicode object.

test_subprocess.test_leaking_fds_on_error() failed when the PATH
environment variable contains a path to an existing file. Fix the
test: ignore also ENOTDIR, not only ENOENT and EACCES.

(cherry picked from commit 131fd7f9)

glibc is deprecating libcrypt in favor of libxcrypt, however python assumes
that crypt.h will always be included. This change makes the header inclusion
explicit when libxcrypt is present on the system.
(cherry picked from commit e768c86e)

It should be `urllib2.URLError` instead of just `URLError`.

This test doesn't care about order, the underlying filesystem APIs do not
guarantee directory listings on subsequent calls will be in the same order.

(cherry picked from commit 7d91c025)

See https://msdn.microsoft.com/en-us/library/windows/desktop/aa365247(v=vs.85).aspx?f=255&MSPPError=-2147217396#maxpath

Paths that begin with `\\?\` are "extended-length paths".

glibc has removed Sun RPC. Use replacement libtirpc headers and library in
nis module
Signed-off-by: Christian Heimes <christian@python.org>
(cherry picked from commit f3031b8a)

It's more trouble than it's worth, since AppVeyor only checks the HEAD commit of a PR rather than the full diff against the base branch to decide which files changed.
(cherry picked from commit 7f7de371)

(cherry picked from commit 65f2a6dc)

(cherry picked from commit 1e6d8525f9dd3dcdc83adb93b164082c8b95d17a)

830daae1 added some new GIL-releasing to new_buffersize. This is fine, but it's better to avoid reacquiring the GIL for as long as possible. Also, it should use FILE_(BEGIN|END)_ALLOW_THREADS to avoid having the file closed from under it.

Multiple threads iterating over a file can corrupt the file's internal readahead
buffer resulting in crashes. To fix this, cache buffer state thread-locally for
the duration of a file_iternext call and only update the file's internal state
after reading completes.

No attempt is made to define or provide "reasonable" semantics for iterating
over a file on multiple threads. (Non-crashing) races are still
present. Duplicated, corrupt, and missing data will happen.

This was originally fixed by 6401e567, which
raised an exception from seek() and next() when concurrent operations were
detected. Alas, this simpler solution breaks legitimate use cases such as
capturing the standard streams when multiple threads are logging.

Updates documentation for generator expressions in classes tutorial: Clarify usage of ambiguous term "brackets" by replacing with "square brackets". Updated subsequent lines to respect line breaks. (GH-5079)
(cherry picked from commit f190eb59)

(cherry picked from commit 7cc42c35)

Move other test to more proper place.
(cherry picked from commit e8ed9655)

(cherry picked from commit fe90efdc07ec70fd4ff28eac179448a41379cff1)

select.error doesn't have an errno attribute so access the errno by
indexing instead.

(cherry picked from commit e3256087)

(cherry picked from commit e5f7dcce)

(cherry picked from commit 53f91356)

(cherry picked from commit d11e8e0d)

This is more complicated than it should be because we need to preserve the
useful mtime-based regeneration feature that lib2to3.pgen2.driver.load_grammar
has. We only look for the pickled grammar file with pkgutil.get_data and only if
the source file does not exist..
(cherry picked from commit 8a587716)