maria-developers team mailing list archive

[Sergey Petrunya <psergey@xxxxxxxxxxxx>]

Hi Timour,

Ok to push.

On Tue, Aug 23, 2011 at 03:41:55PM +0300, timour@xxxxxxxxxxxx wrote:
> At file:///home/tsk/mprog/src/5.3/
> 
> ------------------------------------------------------------
> revno: 3166
> revision-id: timour@xxxxxxxxxxxx-20110823123915-jxf9hvxq2hy03rr7
> parent: timour@xxxxxxxxxxxx-20110822210013-egubev0wgyi00wjt
> fixes bug(s): https://launchpad.net/bugs/825018
> committer: timour@xxxxxxxxxxxx
> branch nick: 5.3
> timestamp: Tue 2011-08-23 15:39:15 +0300
> message:
>   Fixed bug lp:825018
>   
>   Analysis:
>   During the first execution of the query through the stored
>   procedure, the optimization phase calls
>   substitute_for_best_equal_field(), which calls
>   Item_in_optimizer::transform(). The latter replaces
>   Item_in_subselect::left_expr with args[0] via assignment.
>   In this test case args[0] is an Item_outer_ref which is
>   created/deallocated for each re-execution. As a result,
>   during the second execution Item_in_subselect::left_expr
>   pointed to freed memory, which resulted in a crash.
>   
>   Solution:
>   The solution is to use change_item_tree(), so that the
>   origianal left expression is restored after each execution.

BR
 Sergey
-- 
Sergey Petrunia, Software Developer
Monty Program AB, http://askmonty.org
Blog: http://s.petrunia.net/blog