From 21f819db8604606e5412040135ad5eb4d0d2d364 Mon Sep 17 00:00:00 2001
From: Raymond Hettinger <python@rcn.com>
Date: Sat, 30 Aug 2003 00:11:16 +0000
Subject: [PATCH] For safety, replace a tuple entry before decreffing it.

---
 Modules/itertoolsmodule.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/Modules/itertoolsmodule.c b/Modules/itertoolsmodule.c
index 4f49fefb28bc..de7939d6fb9f 100644
--- a/Modules/itertoolsmodule.c
+++ b/Modules/itertoolsmodule.c
@@ -1597,6 +1597,7 @@ izip_next(izipobject *lz)
 	PyObject *result = lz->result;
 	PyObject *it;
 	PyObject *item;
+	PyObject *olditem;
 
 	if (result->ob_refcnt == 1) {
 		Py_INCREF(result);
@@ -1608,8 +1609,9 @@ izip_next(izipobject *lz)
 				Py_DECREF(result);
 				return NULL;
 			}
-			Py_DECREF(PyTuple_GET_ITEM(result, i));
+			olditem = PyTuple_GET_ITEM(result, i);
 			PyTuple_SET_ITEM(result, i, item);
+			Py_DECREF(olditem);
 		}
 	} else {
 		result = PyTuple_New(tuplesize);
-- 
2.47.3