Fix an edge case whereby the __del__() method of a classic class could
create a new weakref to the object.
diff --git a/Objects/classobject.c b/Objects/classobject.c
index 89cca59..b4b17f9 100644
--- a/Objects/classobject.c
+++ b/Objects/classobject.c
@@ -646,6 +646,16 @@
*/
assert(inst->ob_refcnt > 0);
if (--inst->ob_refcnt == 0) {
+
+ /* New weakrefs could be created during the finalizer call.
+ If this occurs, clear them out without calling their
+ finalizers since they might rely on part of the object
+ being finalized that has already been destroyed. */
+ while (inst->in_weakreflist != NULL) {
+ _PyWeakref_ClearRef((PyWeakReference *)
+ (inst->in_weakreflist));
+ }
+
Py_DECREF(inst->in_class);
Py_XDECREF(inst->in_dict);
PyObject_GC_Del(inst);