Fix for bug #5890 "Triggers fail for DELETE without WHERE".

If we have DELETE with always true WHERE clause we should not use 
optimized delete_all_rows() method for tables with DELETE triggers,
because in this case we will lose side-effect of deletion.


mysql-test/r/trigger.result:
  Added test for bug #5890 "Triggers fail for DELETE without WHERE".
mysql-test/t/trigger.test:
  Added test for bug #5890 "Triggers fail for DELETE without WHERE".
sql/sql_delete.cc:
  mysql_delete(): 
    We should not use optimized delete_all_rows() method for tables
    with DELETE triggers, because in this case we will lose side-effect
    of deletion.
sql/sql_trigger.h:
  Added new Table_triggers_list::has_delete_triggers() method which
  allows to understand quickly if we have some DELETE triggers in
  our list.

1 files changed, 6 insertions, 0 deletions

diff --git a/sql/sql_trigger.h b/sql/sql_trigger.h
index 8ab2ab003f8..d0376f056d9 100644
--- a/sql/sql_trigger.h
+++ b/sql/sql_trigger.h
@@ -58,5 +58,11 @@ public:
   static bool check_n_load(THD *thd, const char *db, const char *table_name,
                            TABLE *table);
 
+  bool has_delete_triggers()
+  {
+    return (bodies[TRG_EVENT_DELETE][TRG_ACTION_BEFORE] ||
+            bodies[TRG_EVENT_DELETE][TRG_ACTION_AFTER]);
+  }
+
   friend class Item_trigger_field;
 };