This is a partial fix to the issue of servers disconnecting unexpectedly; in
this case the 421 says they are disconnecting, so we close the socket and
return the 421 in the appropriate error context.

Original patch by Mark Sapiro, updated by Kushal Das, with additional
tests by me.

#17471 - Increasing the urllib.error test coverage. Bringing it to 100%. Based on patch contributed by Daniel Wozniak

Structured Exception Handling on windows.

I have no idea how one would write a test for this.

Patch by July Tikhonov.

In Python2 Popen uses *FILE objects, which wind up buffering even though
subprocess defaults to no buffering.  In Python3, subprocess streams really
are unbuffered by default, but the imaplib code assumes read is buffered.  This
patch uses the default buffer size from the io module to get buffered streams
from Popen.

Much debugging work and patch by Diane Trout.

The imap protocol is too complicated to write a test for this simple
change with our current level of test infrastructure.

This fixes a regression relative to Python2.  (In 2, methods on a class were
unbound methods and matched the inspect queries being done, in 3 they are just
functions and so were missed).

This is an undocumented function that pydoc itself does not use, but
I found that numpy at least uses it in its documentation generator.

Original patch by Matt Bachmann.

specifically addresses a stack misalignment issue on x86 and issues on
some more recent platforms.

Patch by Rafael Santos.

Original patch by Kushal Das.

the sentence referred to. Make other minor edits to improve flow.

caching of compiled regular expressions.

Initial patch contributed by Edmond Burnett.

urllib.parse.unquote() and urllib.parse.unquote_to_bytes().

If PYTHON is undefined, this fails without the launcher (installed with 3.3 or
from PyPI), but this is better than always failing. Patch from Zachary Ware.

#17368: Fix an off-by-one error in the Python JSON decoder that caused a failure while decoding empty object literals when object_pairs_hook was specified.

as reported by Serhiy Storchaka and Matthew Barnett.

as reported by Serhiy Storchaka and Matthew Barnett.

found by Serhiy Storchaka and Matthew Barnett