Fix for #1303614 and #1174712:
- __dict__ descriptor abuse for subclasses of built-in types
- subclassing from both ModuleType and another built-in types

the implementation for __reduce__ and __reduce_ex__ into two separate
functions. Fixes bug #931877.
 (backport from rev. 54397)

name. Remove a reference leak that happened if the name could not be
converted to string.
 (backport from rev. 54378)

__dict__ and __weakref__ are removed from the slots tuple earlier
in the code, in the loop that mangles slot names.
 (backport from rev. 54270)

segfault the interpreter during weakref clean up.  Now any new weakrefs created
after __del__ is run are removed silently.

Fixes bug #1377858 and the weakref_in_del crasher for new-style classes.
Classic classes are still affected.

* unified the way intobject, longobject and mystrtoul handle
  values around -sys.maxint-1.

* in general, trying to entierely avoid overflows in any computation
  involving signed ints or longs is extremely involved.  Fixed a few
  simple cases where a compiler might be too clever (but that's all
  guesswork).

* more overflow checks against bad data in marshal.c.

* 2.5 specific: fixed a number of places that were still confusing int
  and Py_ssize_t.  Some of them could potentially have caused
  "real-world" breakage.

* list.pop(x): fixing overflow issues on x was messy.  I just reverted
  to PyArg_ParseTuple("n"), which does the right thing.  (An obscure
  test was trying to give a Decimal to list.pop()... doesn't make
  sense any more IMHO)

* trying to write a few tests...

keyword arguments any more (previously they accepted them, but didn't
use them).
 (backport from rev. 52058)

were failing due to inappropriate clipping of numbers larger than 2**31
with new-style classes. (typeobject.c)  In reviewing the code for classic
classes, there were 2 problems.  Any negative value return could be returned.
Always return -1 if there was an error.  Also make the checks similar
with the new-style classes.  I believe this is correct for 32 and 64 bit
boxes, including Windows64.

Add a test of classic classes too.

I modified this patch some by fixing style, some error checking, and adding
XXX comments.  This patch requires review and some changes are to be expected.
I'm checking in now to get the greatest possible review and establish a
baseline for moving forward.  I don't want this to hold up release if possible.

  value is obtained by invoking hash on the long int.
Fixes #1536021.

Many (all?) of these could be backported.

The problem of checking too eagerly for recursive calls is the
following: if a RuntimeError is caused by recursion, and if code needs
to normalize it immediately (as in the 2nd test), then
PyErr_NormalizeException() needs a call to the RuntimeError class to
instantiate it, and this hits the recursion limit again...  causing
PyErr_NormalizeException() to never finish.

Moved this particular recursion check to slot_tp_call(), which is not
involved in instantiating built-in exceptions.

Backport candidate.

with PyObject_CallFunctionObjArgs, which is 30% faster.

__delitem__, __setslice__ and __delslice__ hooks. This caused test_weakref
and test_userlist to fail in the p3yk branch (where UserList, like all
classes, is new-style) on amd64 systems, with open-ended slices: the
sys.maxint value for empty-endpoint was transformed into -1.

using a custom, nearly-identical macro. This probably changes how some of
these functions are compiled, which may result in fractionally slower (or
faster) execution. Considering the nature of traversal, visiting much of the
address space in unpredictable patterns, I'd argue the code readability and
maintainability is well worth it ;P

tp_clear methods.

solution) in the same way as listobject.c got changed. Hoping for a better
solution.

This was mostly written by Travis Oliphant.
I've inspected it all; Neal Norwitz and MvL have also looked at it
(in an earlier incarnation).

Add (int) casts to silence compiler warnings.
Raise Python exceptions for overflows.

Convert Py_ssize_t using PyInt_FromSsize_t

A patch by mwh to check that user-defined mro's are reasonable
enough.

* set sq_repeat and sq_concat to NULL for user-defined new-style
  classes, as a way to fix a number of related problems.  See
  test_descr.notimplemented()).  One of these problems was fixed
  in r25556 and r25557 but many more existed; this is a general
  fix and thus reverts r25556-r25557.

* to avoid having PySequence_Repeat()/PySequence_Concat() failing
  on user-defined classes, they now fall back to nb_add/nb_mul if
  sq_concat/sq_repeat are not defined and the arguments appear to
  be sequences.

* added tests.

Backport candidate.

In C++, it's an error to pass a string literal to a char* function
without a const_cast().  Rather than require every C++ extension
module to put a cast around string literals, fix the API to state the
const-ness.

I focused on parts of the API where people usually pass literals:
PyArg_ParseTuple() and friends, Py_BuildValue(), PyMethodDef, the type
slots, etc.  Predictably, there were a large set of functions that
needed to be fixed as a result of these changes.  The most pervasive
change was to make the keyword args list passed to
PyArg_ParseTupleAndKewords() to be a const char *kwlist[].

One cast was required as a result of the changes:  A type object
mallocs the memory for its tp_doc slot and later frees it.
PyTypeObject says that tp_doc is const char *; but if the type was
created by type_new(), we know it is safe to cast to char *.