Fixes #1591996. Patch contributed by Neal Norwitz.

Bug #1588287: fix invalid assertion for `1,2` in debug builds.

bdist_rpm

Fixes #1557890.

Backported from trunk.

section with a link to the tutorial sections.

Backported from trunk.

the tuple isn't used as the "exception arguments tuple".
 (backport from rev. 52535)

 (backport from rev. 52532)

 (backport from rev. 52529)

 (backport from rev. 52527)

GNU modes.
 (backport from rev. 52524)

subprocess.
 (backport from rev. 52522)

fix all codecs file wrappers to work correctly with the "with"
statement (bug #1586513).
 (backport from rev. 52517)

Don't inline Py_ADDRESS_IN_RANGE with gcc 4+ either.

Prevent crash if alloc of garbage fails.  Found by Typo.pl.

Fix bug #1565514, SystemError not raised on too many nested blocks.
It seems like this should be a different error than SystemError, but
I don't have any great ideas and SystemError was raised in 2.4 and earlier.

Fix crash in test on HP-UX.  Apparently, it's not possible to delete a lock if
it's held (even by the current thread).

Fix warnings with HP's C compiler.  It doesn't recognize that infinite
loops are, um, infinite.  These conditions should not be able to happen.

Add some asserts.  In sysmodule, I think these were to try to silence
some warnings from Klokwork.  They verify the assumptions of the format
of svn version output.

The assert in the thread module helped debug a problem on HP-UX.

 (backport from rev. 52497)

 (backport from rev. 52488)

not the posix error code; with test.
Fixes #1576174.

Backported from trunk, revision 52485.

base64.encodestring() for encoding authentication data.
encodestring() can include newlines for very long input, which
produced broken HTTP headers.

2.4 backport candidate, probably.

[Bug #1575506] The _singlefileMailbox class was using the wrong file object in its flush() method, causing an error

Point users to the subprocess module in the docs for os.system, os.spawn*, os.popen2, and the popen2 and commands modules

[Bug #1542016] Report PCALL_POP value.  This makes the return value of sys.callstats() match its docstring.

Backport candidate.  Though it's an API change, this is a pretty obscure
portion of the API.

Patch #1549049: Rewrite type conversion in structmember.
Fixes #1545696 and #1566140.

The new warnings have been omitted in the backport.