Fix merge (5.0 -> 5.1) of the patch for BUG#15166/15196.

mysql-test/r/trigger-grant.result:
  Updated result file: use TRIGGER instead of SUPER for BUG#15166/15196 tests.
sql/item.cc:
  Updated according to the 5.1 data structures.

mysql-test/r/trigger-grant.result

@@ -195,18 +195,16 @@ CREATE TABLE t3(col CHAR(20));
 CREATE TABLE t4(col CHAR(20));
 CREATE USER mysqltest_u1@localhost;
 REVOKE ALL PRIVILEGES, GRANT OPTION FROM mysqltest_u1@localhost;
-GRANT SUPER ON *.* TO mysqltest_u1@localhost;
-GRANT SELECT ON mysqltest_db1.t1 TO mysqltest_u1@localhost;
+GRANT TRIGGER ON mysqltest_db1.* TO mysqltest_u1@localhost;
 SET @mysqltest_var = NULL;
 
 ---> connection: default
 use mysqltest_db1;
-REVOKE SELECT ON mysqltest_db1.t1 FROM mysqltest_u1@localhost;
 GRANT DELETE ON mysqltest_db1.* TO mysqltest_u1@localhost;
 SHOW GRANTS FOR mysqltest_u1@localhost;
 Grants for mysqltest_u1@localhost
-GRANT SUPER ON *.* TO 'mysqltest_u1'@'localhost'
-GRANT DELETE ON `mysqltest_db1`.* TO 'mysqltest_u1'@'localhost'
+GRANT USAGE ON *.* TO 'mysqltest_u1'@'localhost'
+GRANT DELETE, TRIGGER ON `mysqltest_db1`.* TO 'mysqltest_u1'@'localhost'
 
 ---> connection: bug15166_u1_con
 use mysqltest_db1;

sql/item.cc

@@ -5324,8 +5324,8 @@ bool Item_trigger_field::fix_fields(THD *thd, Item **items)
       table_grants->want_privilege=
         access_type == AT_READ ? SELECT_ACL : UPDATE_ACL;
 
-      if (check_grant_column(thd, table_grants, triggers->table->s->db,
-                             triggers->table->s->table_name, field_name,
+      if (check_grant_column(thd, table_grants, triggers->table->s->db.str,
+                             triggers->table->s->table_name.str, field_name,
                              strlen(field_name), thd->security_ctx))
         return TRUE;
     }