do not use '' as user in tests, because it picks the Unix login (which gives unexpected results if it is 'root')
(such behaviour is a feature of mysql_real_connect(), see the manual).
'SHOW GRANTS' syntax is added
'SHOW GRANTS FOR CURRENT_USER' syntax is added
'SHOW GRANTS FOR CURRENT_USER()' syntax is added
CURRENT_USER without parens in expressions(SELECT CURRENT_USER;)
Call pthread_mutex_destroy() on not used mutex.
Changed comments in .h and .c files from // -> /* */
Added detection of mutex on which one didn't call pthread_mutex_destroy()
Fixed bug in create_tmp_field() which causes a memory overrun in queries that uses "ORDER BY constant_expression"
Added optimisation for ORDER BY NULL
