Hi Igor, I have been trying to figure out the problems you see in the mysql_client_test test case in the MariaDB 5.1 tree. It has been tricky due to not being able to reproduce. Patrick Crews was able to reproduce though, and was helpful enough to file this bug with some additional info: https://bugs.launchpad.net/maria/+bug/363181
From this information, I pushed a few minor fixes to the Launchpad tree (two missing DBUG_RETURN statements). After this push, Patrick can no longer reproduce the failure.
So, while my fixes were done in the area of the code where the problem seems to occur, I don't understand why two missing DBUG_RETURN would cause the error we saw... Maybe you can try again to see if you can reproduce the bug in the latest tree? If you cannot, then we may have to consider the problem fixed for now. If you can still reproduce, it would be very helpful if you could reproduce it with dbug enabled: perl mysql-test-run.pl --debug mysql_client_test and collect all the *.trace and *.err files from mysql-test/var/ and attach them to the bug or email them. It would be good to get progress on this annoying problem. - Kristian.