Add an early-out for deque_clear()

rhettinger · rhettinger · commit 38031143fbab · 2015-09-29T22:45:05.000-07:00
diff --git a/Modules/_collectionsmodule.c b/Modules/_collectionsmodule.c
@@ -595,6 +595,9 @@ deque_clear(dequeobject *deque)
     Py_ssize_t n;
     PyObject *item;
 
+    if (Py_SIZE(deque) == 0)
+        return;
+
     /* During the process of clearing a deque, decrefs can cause the
        deque to mutate.  To avoid fatal confusion, we have to make the
        deque empty before clearing the blocks and never refer to
