Merge p3yk branch with the trunk up to revision 45595. This breaks a fair

number of tests, all because of the codecs/_multibytecodecs issue described
here (it's not a Py3K issue, just something Py3K discovers):
http://mail.python.org/pipermail/python-dev/2006-April/064051.html

Hye-Shik Chang promised to look for a fix, so no need to fix it here. The
tests that are expected to break are:

test_codecencodings_cn
test_codecencodings_hk
test_codecencodings_jp
test_codecencodings_kr
test_codecencodings_tw
test_codecs
test_multibytecodec

This merge fixes an actual test failure (test_weakref) in this branch,
though, so I believe merging is the right thing to do anyway.

Objects/structseq.c

@@ -315,7 +315,7 @@ static PyTypeObject _struct_sequence_template = {
 	0,					/* tp_as_number */
 	&structseq_as_sequence,			/* tp_as_sequence */
 	0,					/* tp_as_mapping */
-	(hashfunc)structseq_hash,              	/* tp_hash */
+	structseq_hash,				/* tp_hash */
 	0,              			/* tp_call */
 	0,					/* tp_str */
 	0,                       		/* tp_getattro */
@@ -349,6 +349,14 @@ PyStructSequence_InitType(PyTypeObject *type, PyStructSequence_Desc *desc)
 	PyMemberDef* members;
 	int n_members, n_unnamed_members, i, k;
 
+#ifdef Py_TRACE_REFS
+	/* if the type object was chained, unchain it first
+	   before overwriting its storage */
+	if (type->_ob_next) {
+		_Py_ForgetReference((PyObject*)type);
+	}
+#endif
+
 	n_unnamed_members = 0;
 	for (i = 0; desc->fields[i].name != NULL; ++i)
 		if (desc->fields[i].name == PyStructSequence_UnnamedField)