Merge mockturtle.local:/home/dlenev/src/mysql-5.0-bg20670-2

into  mockturtle.local:/home/dlenev/src/mysql-5.1-bg20670

mysql-test/r/trigger.result

@@ -1173,4 +1173,16 @@ TRIGGER t2_bi BEFORE INSERT ON t2 FOR EACH ROW SET @a = 2;
 ERROR HY000: String '1234567890abcdefghij1234567890abcdefghij1234567890abcdefghijQWERTY' is too long for host name (should be no longer than 60)
 DROP TABLE t1;
 DROP TABLE t2;
+drop table if exists t1;
+create table t1 (i int, j int key);
+insert into t1 values (1,1), (2,2), (3,3);
+create trigger t1_bu before update on t1 for each row
+set new.j = new.j + 10;
+update t1 set i= i+ 10 where j > 2;
+select * from t1;
+i	j
+1	1
+2	2
+13	13
+drop table t1;
 End of 5.0 tests

mysql-test/t/trigger.test

@@ -1421,4 +1421,23 @@ DROP TABLE t1;
 DROP TABLE t2;
 
 
+#
+# Bug#20670 "UPDATE using key and invoking trigger that modifies
+#            this key does not stop"
+#
+
+--disable_warnings
+drop table if exists t1;
+--enable_warnings
+create table t1 (i int, j int key);
+insert into t1 values (1,1), (2,2), (3,3);
+create trigger t1_bu before update on t1 for each row
+  set new.j = new.j + 10;
+# This should not work indefinitely and should cause
+# expected result
+update t1 set i= i+ 10 where j > 2;
+select * from t1;
+drop table t1;
+
+
 --echo End of 5.0 tests

sql/sql_trigger.cc

@@ -1582,6 +1582,38 @@ void Table_triggers_list::mark_fields_used(trg_event_type event)
 }
 
 
+/*
+  Check if field of subject table can be changed in before update trigger.
+
+  SYNOPSIS
+    is_updated_in_before_update_triggers()
+      field  Field object for field to be checked
+
+  NOTE
+    Field passed to this function should be bound to the same
+    TABLE object as Table_triggers_list.
+
+  RETURN VALUE
+    TRUE   Field is changed
+    FALSE  Otherwise
+*/
+
+bool Table_triggers_list::is_updated_in_before_update_triggers(Field *fld)
+{
+  Item_trigger_field *trg_fld;
+  for (trg_fld= trigger_fields[TRG_EVENT_UPDATE][TRG_ACTION_BEFORE];
+       trg_fld != 0;
+       trg_fld= trg_fld->next_trg_field)
+  {
+    if (trg_fld->get_settable_routine_parameter() &&
+        trg_fld->field_idx != (uint)-1 &&
+        table->field[trg_fld->field_idx]->eq(fld))
+      return TRUE;
+  }
+  return FALSE;
+}
+
+
 /*
   Trigger BUG#14090 compatibility hook
 

sql/sql_trigger.h

@@ -116,11 +116,6 @@ public:
             bodies[TRG_EVENT_DELETE][TRG_ACTION_AFTER]);
   }
 
-  bool has_before_update_triggers()
-  {
-    return test(bodies[TRG_EVENT_UPDATE][TRG_ACTION_BEFORE]);
-  }
-
   void set_table(TABLE *new_table);
 
   void mark_fields_used(trg_event_type event);