A review of overflow-detecting code in the 2.4 branch. * 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.

--- a/Objects/stringobject.c	Wed Oct 04 09:18:51 2006 +0000
+++ b/Objects/stringobject.c	Wed Oct 04 10:13:32 2006 +0000
@@ -799,7 +799,7 @@
 	register PyStringObject* op = (PyStringObject*) obj;
 	size_t newsize = 2 + 4 * op->ob_size;
 	PyObject *v;
-	if (newsize > INT_MAX) {
+	if (newsize > INT_MAX || newsize / 4 != op->ob_size) {
 		PyErr_SetString(PyExc_OverflowError,
 			"string is too large to make repr");
 	}