Issue #23576: Avoid stalling in SSL reads when EOF has been reached in the SSL layer but the underlying connection hasn't been closed.

These functions are not documented but used in third-party code.

See
de Gouw, Stijn and Rot, Jurriaan and de Boer, Frank S and Bubel, Richard and Hähnle, Reiner
"OpenJDK’s java.utils.Collection.sort() is broken: The good, the bad and the worst case"

set to non inheritable

closing the window.

particular accepts writable memoryview).

conditional group references are used in lookbehind assertions in regular
expressions.

consumed too much memory and raised SystemError or MemoryError.
Original patch by Aleksi Torhamo.

flush() was not called in close() if closefd=False.

docstrings.

Initial patch by Yuyang Guo.

overflows.  Added few missed PyErr_NoMemory().

module.  Original patch by Claudiu Popa.

when run as root.  Extended testing with /dev/full.
Based on patch by Daniel Dickman.

and email.test.

Patch by David Edelsohn.

the multiprocessing module.

posixpath.expandvars().  Fixed all os.path implementations on
unicode-disabled builds.

Fixes a regression in issue #22765.  Patch by Vinson Lee.