The changes to Doc/library/unittest.mock.rst are almost entirely a
selective backport of the 3.5 page.

on OS X.  Original patch by André Freitas.

A deprecation warning no longer issued by XMLParser subclass with default
doctype() method.  Direct call of doctype() now issues a warning.  Parser's
doctype() now is not called if target's doctype() is called.  Based on patch
by Martin Panter.

object now always allocates place for trailing null byte and it's buffer now
is always null-terminated.

functions of the audioop module.

keyword arguments called "func" and "self".  Patch by Martin Panter.

Issue #23684: Clarify the return value of the scheme attribute of ParseResult and SplitResult objects.

Patch by Martin Panter.