From 796fc992ce99fc581d635bea6bdf7f7efeb3c477 Mon Sep 17 00:00:00 2001
From: Armin Rigo <arigo@tunes.org>
Date: Thu, 19 Apr 2007 14:56:48 +0000
Subject: [PATCH] Fix a usage of the dangerous pattern decref - modify field -
 incref.

---
 Objects/typeobject.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/Objects/typeobject.c b/Objects/typeobject.c
index a3b1476a8d5..89d2d4f9813 100644
--- a/Objects/typeobject.c
+++ b/Objects/typeobject.c
@@ -265,9 +265,10 @@ type_set_bases(PyTypeObject *type, PyObject *value, void *context)
 			PyObject* mro;
 			PyArg_UnpackTuple(PyList_GET_ITEM(temp, i),
 					 "", 2, 2, &cls, &mro);
-			Py_DECREF(cls->tp_mro);
+			Py_INCREF(mro);
+			ob = cls->tp_mro;
 			cls->tp_mro = mro;
-			Py_INCREF(cls->tp_mro);
+			Py_DECREF(ob);
 		}
 		Py_DECREF(temp);
 		goto bail;