#11335: Fix memory leak after key function failure in sort

Lib/test/test_sort.py

@@ -111,6 +111,12 @@ class TestBase(unittest.TestCase):
             s.sort(key=CmpToKey(lambda a, b:  int(random.random() * 3) - 1))
             check("an insane function left some permutation", x, s)
 
+            if len(x) >= 2:
+                def bad_key(x):
+                    raise RuntimeError
+                s = x[:]
+                self.assertRaises(RuntimeError, s.sort, key=bad_key)
+
             x = [Complains(i) for i in x]
             s = x[:]
             random.shuffle(s)

Objects/listobject.c

@@ -1944,6 +1944,8 @@ listsort(PyListObject *self, PyObject *args, PyObject *kwds)
             if (keys[i] == NULL) {
                 for (i=i-1 ; i>=0 ; i--)
                     Py_DECREF(keys[i]);
+                if (keys != &ms.temparray[saved_ob_size+1])
+                    PyMem_FREE(keys);
                 goto keyfunc_fail;
             }
         }