Fix a possible refleak in tupleobject.c (GH-19018)

miss-islington · shihai1991 · web-flow · commit 890dcfe40358 · 2020-03-15T12:55:39.000-07:00
(cherry picked from commit c81609e) Co-authored-by: Hai Shi <shihai1992@gmail.com>
diff --git a/Objects/tupleobject.c b/Objects/tupleobject.c
@@ -719,8 +719,10 @@ tuple_subtype_new(PyTypeObject *type, PyObject *iterable)
         return NULL;
     assert(PyTuple_Check(tmp));
     newobj = type->tp_alloc(type, n = PyTuple_GET_SIZE(tmp));
-    if (newobj == NULL)
+    if (newobj == NULL) {
+        Py_DECREF(tmp);
         return NULL;
+    }
     for (i = 0; i < n; i++) {
         item = PyTuple_GET_ITEM(tmp, i);
         Py_INCREF(item);
