first step towards removing the %f -> %g switch (see issues 7117,
5859).

characters.

closes the internal file object in case of an error (issue #7341).

(Note that an empty archive is not the same as an empty file. An
empty archive contains no members and is correctly terminated with an
EOF block full of zeros. An empty file contains no data at all.)

The problem was that although tarfile was able to create empty
archives, it failed to open them raising a ReadError. On the other
hand, tarfile opened empty files without error in most read modes and
presented them as empty archives. (However, some modes still raised
errors: "r|gz" raised ReadError, but "r:gz" worked, "r:bz2" even
raised EOFError.)

In order to get a more fine-grained control over the various internal
error conditions I now split up the HeaderError exception into a
number of meaningful sub-exceptions. This makes it easier in the
TarFile.next() method to react to the different conditions in the
correct way.

The visible change in its behaviour now is that tarfile will open
empty archives correctly and raise ReadError consistently for empty
files.

issue5738: The distribution example was confusing, and out of date. It's too large to include inline in the docs as well. It belongs in an addons module outside the stdlib. Removing.

properly, and use this to skip test_multiprocessing on platforms
where sem_open raises a signal.  This should fix some FreeBSD buildbot
failures for test_multiprocessing.

- Fix #7362: give a good error message for parenthesized arguments with
  defaults.

- Add a py3k warning for any parenthesized arguments since those are not allowed
  in Py3.  This warning is not given in tuple unpacking, since that incurs the
  tuple unpacking warning.

(Issue 7179)

On MacOSX 10.6 the CoreFoundation framework must be initialized on the main
thread, the constructor function in that framework will cause an SIGABRT when
it is called on any other thread.

Because a number of extension link (indirectly) to CoreFoundation and the
Python core itself didn't the interpreter crashed when importing some
extensions, such as _locale, on a secondary thread.

This fix ensures that Python is linked to CoreFoundation on OSX, which results
in the CoreFoundation constructor being called when Python is loaded. This
does not require code changes.

constructor in case of an error.

string <-> float conversions;  this makes sure that the result of the round
operation is correctly rounded, and hence displays nicely using the new float
repr.