1 files changed, 4 insertions, 1 deletions
diff --git a/sql/item_func.h b/sql/item_func.h
index 03e67ddf11a..4b1516dcc4d 100644
--- a/sql/item_func.h
+++ b/sql/item_func.h
@@ -167,7 +167,10 @@ public:
                                   Item **item, uint nitems);
   inline bool get_arg0_time(MYSQL_TIME *ltime)
   {
-    return (null_value=args[0]->get_time(ltime));
+    null_value= args[0]->get_time(ltime);
+    DBUG_ASSERT(null_value ||
+                ltime->time_type != MYSQL_TIMESTAMP_TIME || ltime->day == 0);
+    return null_value;
   }
   bool is_null() { 
     update_null_value();