tp_new_wrapper(): A subtle change in the check for safe use.
Allow staticbase != type, as long as their tp_new slots are the same.
diff --git a/Objects/typeobject.c b/Objects/typeobject.c
index 52fd7e9..2a9ef71 100644
--- a/Objects/typeobject.c
+++ b/Objects/typeobject.c
@@ -2303,7 +2303,7 @@
 	staticbase = subtype;
 	while (staticbase && (staticbase->tp_flags & Py_TPFLAGS_HEAPTYPE))
 		staticbase = staticbase->tp_base;
-	if (staticbase != type) {
+	if (staticbase->tp_new != type->tp_new) {
 		PyErr_Format(PyExc_TypeError,
 			     "%s.__new__(%s) is not safe, use %s.__new__()",
 			     type->tp_name,