commit 3aee092ecb53b234073028e3870502713b429f12
author Raymond Hettinger <python@rcn.com> Mon May 11 20:00:25 2015 -0700
committer Raymond Hettinger <python@rcn.com> Mon May 11 20:00:25 2015 -0700
tree b30aa272a3660c07c56c15dcd65be48d6d974a7c
parent 632d692e296bfe980e2b1ba233d168135f3de5f4

Defend against a mutation during comparison

Modules/_heapqmodule.c

diff --git a/Modules/_heapqmodule.c b/Modules/_heapqmodule.c
index d0ddb09..be301a6 100644
--- a/Modules/_heapqmodule.c
+++ b/Modules/_heapqmodule.c
@@ -244,6 +244,11 @@
         return item;
     }
 
+    if (PyList_GET_SIZE(heap) == 0) {
+        PyErr_SetString(PyExc_IndexError, "index out of range");
+        return NULL;
+    }
+
     returnitem = PyList_GET_ITEM(heap, 0);
     Py_INCREF(item);
     PyList_SET_ITEM(heap, 0, item);