When flushing tables, there were a slight chance that the flush was occuring
between processing of two table map events. Since the tables are opened
one by one, it might result in that the tables were not valid and that sub-
sequent locking of tables would cause the slave to crash.
The problem is solved by opening and locking all tables at once using
simple_open_n_lock_tables(). Also, the patch contain a change to open_tables()
so that pre-locking only takes place when the trg_event_map is not zero, which
was not the case before (this caused the lock to be placed in thd->locked_tables
instead of thd->lock since the assumption was that triggers would be called
later and therefore the tables should be pre-locked).
In BUG#30244 added FOUND_ROWS() as an unsafe function, but that
works only in mixed mode under 5.1. There is a workaround that
can be used in statement-based mode either under 5.0 or 5.1
where the result of FOUND_ROWS() is stored into a user vari-
able and used that way instead. This will replicate correctly
even under statement-based replication, since it will write
a User_var entry to the binary log. For some other cases, the
value has to be passed explicitly.
This patch adds tests to demonstrate that the workarounds docu-
mented for statement-based replication works as advertised, and
does more extensive tests for cases that does not work under sta-
tement-based replication actually work under mixed mode by switch-
ing to row-based replication.
