Fix segfault at the first lock action

diff --git a/execution.cc b/execution.cc
index 69b3b2765b845eb0950f75ec3226fc6c62538671..39abc039377504405fd9e7417684317b53d3450a 100644 (file)
--- a/execution.cc
+++ b/execution.cc
@@ -1366,6 +1366,9 @@ ModelAction * ModelExecution::get_last_unlock(ModelAction *curr) const
        void *location = curr->get_location();
 
        action_list_t *list = obj_map.get(location);
+       if (list == NULL)
+               return NULL;
+
        /* Find: max({i in dom(S) | isUnlock(t_i) && samevar(t_i, t)}) */
        sllnode<ModelAction*>* rit;
        for (rit = list->end();rit != NULL;rit=rit->getPrev())