From 74d8d63b183f7bb90da68f45e34259af439922de Mon Sep 17 00:00:00 2001
From: Christian Heimes <christian@cheimes.de>
Date: Sat, 23 Nov 2013 21:05:31 +0100
Subject: [PATCH] Issue #17810: return -1 on error

---
 Modules/_pickle.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Modules/_pickle.c b/Modules/_pickle.c
index b63a7d92c54..6de94ec1bae 100644
--- a/Modules/_pickle.c
+++ b/Modules/_pickle.c
@@ -2941,7 +2941,7 @@ save_frozenset(PicklerObject *self, PyObject *obj)
 
     iter = PyObject_GetIter(obj);
     if (iter == NULL) {
-        return NULL;
+        return -1;
     }
     for (;;) {
         PyObject *item;