Mysql server crashes because unsafe statements warning is wrongly elevated to error,
which is set the error status of Diagnostics_area of the thread in THD::binlog_query().
Yet the caller believes that binary logging shouldn't touch the status, so it will
set the status also later by my_ok(), my_error() or my_message() seperately
according to the execution result of the statement or transaction.
But the status of Diagnostics_area of the thread is allowed to set only once.
Fixed to clear the error wrongly set by binary logging, but keep the warning message.
binlog_format=mixed
Statement-based replication of DELETE ... LIMIT, UPDATE ... LIMIT,
INSERT ... SELECT ... LIMIT is not safe as order of rows is not
defined.
With this fix, we issue a warning that this statement is not safe to
replicate in statement mode, or go to row-based mode in mixed mode.
Note that we may consider a statement as safe if ORDER BY primary_key
is present. However it may confuse users to see very similiar statements
replicated differently.
Note 2: regular UPDATE statement (w/o LIMIT) is unsafe as well, but
this patch doesn't address this issue. See comment from Kristian
posted 18 Mar 10:55.
