src->format are either both NULL or both non-NULL. However, it is safer to
generalize the function. Found by Coverity.

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

Note that the trashcan functions are part of the stable ABI, therefore
they have to be kept around for binary compatibility of extensions.

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 3.2.4
(those which use the trashcan mechanism, despite it being undocumented)
will not be loadable by 3.2.3 and earlier. However, extension modules
compiled for 3.2.3 and earlier will be loadable by 3.2.4.

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

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

Initial patch by Anton Barkovsky, refined a bit by me to further subdivide the
test methods.  Provides tests for the previous two bug fix commits.

This eliminates a ResourceWarning, since before webbrowser was
explicitly opening os.devnull and then leaving it open.  Tests
to follow.

Patch by Anton Barkovsky.

Patch by Anton Barkovsky, comment addition by me.

This shows up as a bug in 3.3 because the definition for Chrome
produces such an empty string.  Tests will follow.

Patch by Anton Barkovsky, comment addition by me.

This showed up as a bug in 3.3 because the definition for Chrome
produced such an empty string.  This fix is tested in 3.3+;
backporting the new test suite is more trouble than it is worth.

Fix window.addch() of the curses module for special characters like
curses.ACS_HLINE: the Python function addch(int) and addch(bytes) is now
calling the C function waddch()/mvwaddch() (as it was done in Python 3.2),
instead of wadd_wch()/mvwadd_wch(). The Python function addch(str) is still
calling the C function wadd_wch()/mvwadd_wch() if the Python curses is linked
to libncursesw.

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.

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.