Bug#26141 mixing table types in trigger causes full
table lock on innodb table

Ensure we do not open and lock tables for the triggers we do not
fire.

create table t1 (c int primary key) engine=innodb;
create table t2 (c int) engine=myisam;
create table t3 (c int) engine=myisam;
insert into t1 (c) values (1);
create trigger trg_bug26141_ai after insert on t1
for each row
begin
insert into t2 (c) values (1);
# We need the 'sync' lock to synchronously wait in connection 2 till 
# the moment when the trigger acquired all the locks.
select release_lock("lock_bug26141_sync") into @a;
# 1000 is time in seconds of lock wait timeout -- this is a way
# to cause a manageable sleep up to 1000 seconds
select get_lock("lock_bug26141_wait", 1000) into @a;
end|
create trigger trg_bug26141_au after update on t1
for each row
begin
insert into t3 (c) values (1);
end|
select get_lock("lock_bug26141_wait", 0);
get_lock("lock_bug26141_wait", 0)
1
select get_lock("lock_bug26141_sync", /* must not be priorly locked */ 0);
get_lock("lock_bug26141_sync", /* must not be priorly locked */ 0)
1
insert into t1 (c) values (2);
select get_lock("lock_bug26141_sync", 1000);
get_lock("lock_bug26141_sync", 1000)
1
update t1 set c=3 where c=1;
select release_lock("lock_bug26141_sync");
release_lock("lock_bug26141_sync")
1
select release_lock("lock_bug26141_wait");
release_lock("lock_bug26141_wait")
1
select * from t1;
c
2
3
select * from t2;
c
1
select * from t3;
c
1
drop table t1, t2, t3;