We were not honouring load_tests in a package/__init__.py when that was the
start_dir parameter, though we do when it is a child package. The fix required
a little care since it introduces the possibility of infinite recursion.

Patch by Alex Gaynor with some modifications by me.

and above.  Patch by Tim Graham.

and above.  Patch by Tim Graham.

Issue #22335: Fix crash when trying to enlarge a bytearray to 0x7fffffff bytes on a 32-bit platform.

Issue #22335: Fix crash when trying to enlarge a bytearray to 0x7fffffff bytes on a 32-bit platform.

#22751: fix test___all__ warning about modified environment in the tests.  Patch by Michael Cetrulo.

When running tests in subprocesses with the regrtest -j option, a bug
in Cocoa Tk can result in a Tcl segfault.  Avoid the problem by forcing
Tk to fully initialize as an OS X gui process before destroying the
Tcl instance and creating another. (Original patch by Serhiy Storchaka)