--- a/mercurial/parsers.c	Wed Sep 17 11:00:03 2014 -0700
+++ b/mercurial/parsers.c	Wed Sep 24 13:16:20 2014 -0700
@@ -854,7 +854,7 @@
 {
 	Py_ssize_t i, len, addlen;
 	char *nothead = NULL;
-	PyObject *heads;
+	PyObject *heads = NULL;
 	PyObject *filter = NULL;
 	PyObject *filteredrevs = Py_None;