mariadb/mysql-test/t/bug41756.test

--source include/have_innodb.inc
--echo #
--echo # Bug#41756 Strange error messages about locks from InnoDB
--echo #
--disable_warnings
drop table if exists t1;
--enable_warnings
--echo # In the default transaction isolation mode, and/or with
--echo # innodb_locks_unsafe_for_binlog=OFF, handler::unlock_row()
--echo # in InnoDB does nothing.
--echo # Thus in order to reproduce the condition that led to the
--echo # warning, one needs to relax isolation by either
--echo # setting a weaker tx_isolation value, or by turning on
--echo # the unsafe replication switch.
--echo # For testing purposes, choose to tweak the isolation level,
--echo # since it's settable at runtime, unlike
--echo # innodb_locks_unsafe_for_binlog, which is
--echo # only a command-line switch.
--echo #
set @@session.tx_isolation="read-committed";

--echo # Prepare data. We need a table with a unique index,
--echo # for join_read_key to be used. The other column
--echo # allows to control what passes WHERE clause filter.
create table t1 (a int primary key, b int) engine=innodb;
--echo # Let's make sure t1 has sufficient amount of rows
--echo # to exclude JT_ALL access method when reading it,
--echo # i.e. make sure that JT_EQ_REF(a) is always preferred.
insert into t1 values (1,1), (2,null), (3,1), (4,1),
                      (5,1), (6,1), (7,1), (8,1), (9,1), (10,1),
                      (11,1), (12,1);
--echo #
--echo # Demonstrate that for the SELECT statement
--echo # used later in the test JT_EQ_REF access method is used.
--echo #
--vertical_results
explain
select 1 from t1 natural join (select 2 as a, 1 as b union all
                               select 2 as a, 2 as b) as t2 for update;
--horizontal_results
--echo #
--echo # Demonstrate that the reported SELECT statement
--echo # no longer produces warnings.
--echo #
select 1 from t1 natural join (select 2 as a, 1 as b union all
                               select 2 as a, 2 as b) as t2 for update;
commit;
--echo # 
--echo # Demonstrate that due to lack of inter-sweep "reset" function,
--echo # we keep some non-matching records locked, even though we know
--echo # we could unlock them.
--echo # To do that, show that if there is only one distinct value
--echo # for a in t2 (a=2), we will keep record (2,null) in t1 locked.
--echo # But if we add another value for "a" to t2, say 6,
--echo # join_read_key cache will be pruned at least once, 
--echo # and thus record (2, null) in t1 will get unlocked.
--echo #
begin;
select 1 from t1 natural join (select 2 as a, 1 as b union all
                               select 2 as a, 2 as b) as t2 for update;
connect (con1,localhost,root,,);
--echo #
--echo # Switching to connection con1
connection con1;
--echo # We should be able to delete all records from t1 except (2, null),
--echo # since they were not locked.
begin;
delete from t1 where a in (1,3,4);
delete from t1 where a in (5,6,7);
delete from t1 where a in (8,9,10);
delete from t1 where a in (11,12);
--echo # 
--echo # Record (2, null) is locked. This is actually unnecessary, 
--echo # because the previous select returned no rows. 
--echo # Just demonstrate the effect.
--echo #
--error ER_LOCK_WAIT_TIMEOUT
delete from t1;
rollback;
--echo #
--echo # Switching to connection default
connection default;
--echo #
--echo # Show that the original contents of t1 is intact:
select * from t1;
commit;
--echo #
--echo # Have a one more record in t2 to show that 
--echo # if join_read_key cache is purned, the current
--echo # row under the cursor is unlocked (provided, this row didn't 
--echo # match the partial WHERE clause, of course).
--echo # Sic: the result of this test dependent on the order of retrieval
--echo # of records --echo # from the derived table, if !
--echo # We use DELETE to disable the JOIN CACHE. This DELETE modifies no
--echo # records. It also should leave no InnoDB row locks.
--echo #
begin;
delete t1.* from t1 natural join (select 2 as a, 2 as b union all
                                  select 0 as a, 0 as b) as t2;
--echo # Demonstrate that nothing was deleted form t1
select * from t1;
--echo #
--echo # Switching to connection con1
connection con1;
begin;
--echo # Since there is another distinct record in the derived table
--echo # the previous matching record in t1 -- (2,null) -- was unlocked.
delete from t1;
--echo # We will need the contents of the table again.
rollback;
select * from t1;
commit;
--echo #
--echo # Switching to connection default
connection default;
commit;
begin;
--echo #
--echo # Before this patch, we could wrongly unlock a record
--echo # that was cached and later used in a join. Demonstrate that
--echo # this is no longer the case.
--echo # Sic: this test is also order-dependent (i.e. the
--echo # the bug would show up only if the first record in the union
--echo # is retreived and processed first.
--echo #
--echo # Verify that JT_EQ_REF is used.
--vertical_results
explain
select 1 from t1 natural join (select 3 as a, 3 as b union all
                               select 3 as a, 1 as b) as t2 for update;
--horizontal_results
--echo # Lock the record.
select 1 from t1 natural join (select 3 as a, 3 as b union all
                               select 3 as a, 2 as b) as t2 for update;
--echo # Switching to connection con1
connection con1;
--echo #
--echo # We should not be able to delete record (3,1) from t1,
--echo # (previously it was possible).
--echo #
--error ER_LOCK_WAIT_TIMEOUT
delete from t1 where a=3;
--echo # Switching to connection default
connection default;
commit;

disconnect con1;
set @@session.tx_isolation=default;
drop table t1;

--echo #
--echo # End of 5.0 tests
--echo #