This was a regression caused by the hash randomization patch.

sporadic crashes in multi-thread programs when several long deallocator
chains ran concurrently and involved subclasses of built-in container
types.

Because of this change, a couple extension modules compiled for 2.7.4
(those which use the trashcan mechanism, despite it being undocumented)
will not be loadable by 2.7.3 and earlier. However, extension modules
compiled for 2.7.3 and earlier will be loadable by 2.7.4.

and io.StringIO objects now raise ValueError when the object has been closed.
Patch by Alessandro Moura.

Before, the type function was called twice in the case where the default
was specified and the argument was given as well.  This was especially
problematic for the FileType type, as a default file would always be
opened, even if a file argument was specified on the command line.

Patch by Arnaud Fontaine, with additional test by Mike Meyer.

Patch by Mike Hoy.

This is done by extending a previous fix for issue #9185 that was made for
Solaris and OpenBSD to NetBSD as well.

Patch by Chris Rebert.

Fix issue 13370: Ensure that ctypes works on Mac OS X when Python is compiled using the clang compiler

Patch by Chris Rebert.

Closes #9374: add back now-unused module attributes; removing them is a backward compatibility issue, since they have a public-seeming name.

(Patch by Ronald Oussoren)

2.7 doesn't support 'a'.  This changeset ports the doc change
and clause-reording portions of Francisco Martín Brugué patch
in order to minimize code base drift.

Patch by Kushal Das.