Applied Sinisa's patch:

"A fix for non-releasing locks for multi table updates and multi
table deletes with InnoDB tables."

mysql-test/r/innodb.result

@@ -1058,6 +1058,12 @@ create table t2 (b varchar(10) not null unique) type=innodb;
 select t1.a from t1,t2 where t1.a=t2.b;
 a
 drop table t1,t2;
+create table t1 (a int not null, b int, primary key (a)) type = innodb;
+create table t2 (a int not null, b int, primary key (a)) type = innodb;
+insert into t1 values (10, 20);
+insert into t2 values (10, 20);
+update t1, t2 set t1.b = 150, t2.b = t1.b where t2.a = t1.a and t1.a = 10;
+drop table t1,t2;
 CREATE TABLE t1 (id INT NOT NULL, PRIMARY KEY (id)) TYPE=INNODB;
 CREATE TABLE t2 (id INT PRIMARY KEY, t1_id INT, INDEX par_ind (t1_id), FOREIGN KEY (t1_id) REFERENCES t1(id)  ON DELETE CASCADE ) TYPE=INNODB;
 insert into t1 set id=1;

mysql-test/t/innodb.test

@@ -696,6 +696,12 @@ create table t1 (a varchar(10) not null) type=myisam;
 create table t2 (b varchar(10) not null unique) type=innodb;
 select t1.a from t1,t2 where t1.a=t2.b;
 drop table t1,t2;
+create table t1 (a int not null, b int, primary key (a)) type = innodb;
+create table t2 (a int not null, b int, primary key (a)) type = innodb;
+insert into t1 values (10, 20);
+insert into t2 values (10, 20);
+update t1, t2 set t1.b = 150, t2.b = t1.b where t2.a = t1.a and t1.a = 10;
+drop table t1,t2;
 
 #
 # Test of multi-table-delete with foreign key constraints

sql/sql_parse.cc

@@ -2038,7 +2038,7 @@ mysql_execute_command(void)
 		       (ORDER *)NULL,(ORDER *)NULL,(Item *)NULL,
 		       (ORDER *)NULL,
 		       select_lex->options | thd->options |
-		       SELECT_NO_JOIN_CACHE,
+		       SELECT_NO_JOIN_CACHE | SELECT_NO_UNLOCK,
 		       result);
       delete result;
     }

sql/sql_update.cc

@@ -400,7 +400,7 @@ int mysql_multi_update(THD *thd,
   res= mysql_select(thd,table_list,total_list,
 		    conds, (ORDER *) NULL, (ORDER *)NULL, (Item *) NULL,
 		    (ORDER *)NULL,
-		    options | SELECT_NO_JOIN_CACHE,
+		    options | SELECT_NO_JOIN_CACHE | SELECT_NO_UNLOCK,
 		    result);
   delete result;
   DBUG_RETURN(res);