seen after a "import multiprocessing.reduction"

An instance of a weakref subclass can have attributes.
If such a weakref holds the only strong reference to the object,
deleting the weakref will delete the object. In this case,
the callback must not be called, because the ref object is being deleted!

Backport of r34309

  conditions in the PyOS_vsnprintf C API function.

This is a backport of r63728 and r63734 from trunk.

now closes its stdout and stderr fds as soon as it is finished with them.

constructors raised an exception.  backportes from trunk c63403.

when open() returns EINVAL.  See issue2158.

reference to themselves.

Backport from trunk.

derive the same default base class.

Backport of r62463.

It seems to work, but will fail at the first flush.

This causes IDLE to silently crash when too many warnings are printed.

Backport of r62448.

Now the code is similar to the one in trunk/.

The behavior was funny:
   >>> print (), repr(())
   (), ()
   >>> print (), repr(())
   (), (...)

  having a self-referential tuple, which is possible from C code.  Nor did
  object's tp_str consider that a type's tp_str could do something that could
  lead to an inifinite recursion.  Py_ReprEnter() and Py_EnterRecursiveCall(),
  respectively, fixed the issues.  (Backport of r58288 from trunk to 2.5.)

remove the now obsoleted assertion.

Prevent PyString_FromStringAndSize() from passing negative sizes on to lower
level memory allocation functions.  Raise a SystemError and return NULL
instead.

Fix zlib crash from zlib.decompressobj().flush(val) when val was not positive.
It tried to allocate negative or zero memory.  That fails.

I have the email trail to prove that George Neville-Neil approved this.
(Backport of r62097.)

Test is run with "regrtest.py -R:: test_compile"

Backport of r62015

"" "" becomes """", which is invalid code.

Backport of r61979.

is stored as a str instance rather than a unicode instance.
Backported from Python 2.6 (see r61904).

explicitly supplied.

Corrected the raw-unicode-escape codec to use UTF-16 surrogates in
this case, like the unicode-escape codec does.

Backport of r61793 and r61853

advertised in the docs.
 (backport from r61712)

and **kwargs expressions could give bogus error messages.

 Fix chown on 64-bit linux.  It needed to take a long (64-bit on 64bit linux) as
 uid and gid input to accept values >=2**31 as valid while still accepting
 negative numbers to pass -1 to chown for "no change".

 Fixes issue1747858.

The behaviour of winsound.Beep() seems to differ between different versions of Windows when there's either:
    a) no sound card entirely
    b) legacy beep driver has been disabled
    c) the legacy beep driver has been uninstalled
Sometimes RuntimeErrors are raised, sometimes they're not.  If _have_soundcard() returns False, don't expect winsound.Beep() to raise a RuntimeError, as this clearly isn't the case, as demonstrated by the various Win32 XP buildbots.

Issue 2321: reduce memory usage (increase the memory that is returned
to the system) by using pymalloc for the data of unicode objects.