setattr() must not convert combined table into split table.

Issue #28383: __hash__ documentation recommends naive XOR to combine but this
is suboptimal. Update the doc to suggest to reuse the hash() method using a
tuple, with an example.

when a GC collection happens in another thread.

Original patch and report by Armin Rigo.

Based on patch by Michael Layzell.

doesn't own its elements as limits.

Patch by Jim Fasarakis-Hilliard.

Patch by Dillon Brock.

form.

for issue #28971.

Imporoved the documentation and tests for make_archive() and unpack_archive().
Improved error handling when corresponding compress module is not available.
Brake circular dependency between shutil and tarfile modules.

PyErr_SyntaxLocationEx() and PyErr_SyntaxLocationObject().

Patch by Julien Palard.

* In Python 3, the specifier is 0o
* There is no special case for leading zeros
* Remove duplicate tests
* Clarify other existing tests and comments

Thanks to Douglas Greiman for the patch.

Issue #28779: multiprocessing.set_forkserver_preload() would crash the forkserver process if a preloaded module instantiated some multiprocessing objects such as locks.

This makes tests passing after changes by issue #5322.

Original patch by Andreas Stührk.

writes the index file when it is not changed.