fix reference leak in count_nextlong

Author: eendebakpt

Modules/itertoolsmodule.c

@@ -3538,9 +3538,10 @@ count_nextlong(countobject *lz)
     if (long_cnt == NULL) {
         /* Switch to slow_mode */
         long_cnt = PyLong_FromSsize_t(PY_SSIZE_T_MAX);
-        lz->long_cnt = long_cnt;
-        if (long_cnt == NULL)
+        if (long_cnt == NULL) {
             return NULL;
+        }
+        lz->long_cnt = long_cnt;
     }
     assert(lz->cnt == PY_SSIZE_T_MAX && long_cnt != NULL);
 

Objects/enumobject.c

@@ -184,11 +184,11 @@ increment_longindex_lock_held(enumobject *en)
         if (next_index == NULL) {
             return NULL;
         }
+        en->en_longindex = next_index;
     }
     assert(next_index != NULL);
     PyObject *stepped_up = PyNumber_Add(next_index, en->one);
     if (stepped_up == NULL) {
-        Py_DECREF(next_index);
         return NULL;
     }
     en->en_longindex = stepped_up;