Spurious `use` statements in output from mysqlbinlog --rewrite-db="a->b"

[Kristian Nielsen]

This bug was introduced with the implementation of MWL#36.

Normally, mysqlbinlog suppresses output of `use` statements before statements
like BEGIN, COMMIT, SAVEPOINT, ROLLBACK, as they are not needed.

However, this suppression does not happen when the MWL#36 --rewrite-db option
affects the current database.

Test case:

    -- source include/have_binlog_format_statement.inc
    -- source include/have_log_bin.inc
    -- source include/have_innodb.inc
    let $MYSQLD_DATADIR= `select @@datadir`;
    create table t1 (a int primary key) engine=innodb;
    create database test2;
    RESET MASTER;
    use test2;
    begin;
    use test;
    insert into t1 values (1);
    use test2;
    commit;
    begin;
    use test;
    insert into t1 values (2);
    use test2;
    commit;
    use test;
    select * from t1 order by a;
    flush logs;
    --exec $MYSQL_BINLOG $MYSQLD_DATADIR/master-bin.000001 --short-form
    --exec $MYSQL_BINLOG $MYSQLD_DATADIR/master-bin.000001 --short-form --rewrite-db="test->foo" --rewrite-db="test2->bar"
    drop database test2;
    drop table t1;

The expected output is that each mysqlbinlog run should output a single `use`
statement, just before the first INSERT. However, currently, the second run
outputs extra `use` statements around the begin/commit statements.

I will commit a fix for 5.2.

[Raghavendra D Prabhu (raghavendra-prabhu)]

rewrite-db has not been ported to PS 5.5 yet, marking it as triaged for 5.5.

[Shahriyar Rzayev (rzayev-sehriyar)]

Percona now uses JIRA for bug reports so this bug report is migrated to: https://jira.percona.com/browse/PS-1841