If a length-1 Unicode string was in the freelist and it was
uninitialized or pointed to a very large (magnitude) negative number,
the check

	 unicode_latin1[unicode->str[0]] == unicode

could cause a segmentation violation, e.g. unicode->str[0] is 0xcbcbcbcb.

Fix this in two ways:

1. Change guard befor unicode_latin1[] to test against 256U.  If I
   understand correctly, the unsigned long used to store UCS4 on my
   box was getting converted to a signed long to compare with the
   signed constant 256.

2. Change _PyUnicode_New() to make sure the first element of str is
   always initialized to zero.  There are several places in the code
   where the caller can exit with an error before initializing any
   of str, which would leave junk in str[0].

Also, silence a compiler warning on pointer vs. int arithmetic.

Bug fix candidate.

hashing a class that does not define __hash__ but does define a
comparison.

The unicode_resize() family only returns -1 or 0 so simply checking
for != 0 is sufficient, but somewhat unclear.  Many Python API
functions return < 0 on error, reserving the right to return 0 or 1 on
success.  Change the call sites for consistency with these calls.

Will backport to 2.3.1

Noted that the SHA algorithm is really SHA-1.
(Contributed by Ronald Rivest.)

Hettinger in comments for issue 804115
https://sourceforge.net/tracker/?func=detail&atid=105470&aid=804115&group_id=5470

* Expanded coverage.

iteritems() is defined.

Backported to 2.3.

Add support for the iterator and mapping protocols.
For Py2.3, this was done for shelve, dumbdbm and other mapping objects, but
not for bsddb and dbhash which were inadvertently missed.

- removed use of the string module
- fixed some broken markup

- update a couple of URLs to point to more recent portions of
  python.org

little better, with similar spacing characteristics with the seealso
environment

(Contributed by George Yoshida.)

- cleaned up some markup

its first three arguments.

Closes RFE #798046 .

module

The documentation severely departed for the actual implementation.

1. Remove "idle" script, it lives in Tools/scripts/ now.
2. Remove shebang from idle.py, should be called explicitly.
3. Remove obsolete test code from rpc.py; needs unit test.