commit 40db90c1ce1a59d5f5f2894bb0ce32110000bf27
author Serhiy Storchaka <storchaka@gmail.com> Thu Apr 20 21:19:31 2017 +0300
committer GitHub <noreply@github.com> Thu Apr 20 21:19:31 2017 +0300
tree 0436658cf04e8ebd902a9bc1851b21ee7b98bf45
parent 8f5cdfa9fc1bb6b4d9a33fc281987252f6398430

bpo-29802: Fix reference counting in module-level struct functions (#1213)

when pass arguments of wrong type.

Objects/unicodeobject.c

diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index ef2215f..b680421 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -3907,6 +3907,7 @@
     PyObject *output = NULL;
     if (arg == NULL) {
         Py_DECREF(*(PyObject**)addr);
+        *(PyObject**)addr = NULL;
         return 1;
     }