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bzr commit into MariaDB 5.1, with Maria 1.5:maria branch (knielsen:2826)
2826 knielsen@xxxxxxxxxxxxxxx 2010-03-09
Fix a buildbot memory leak due to JOIN::destroy() not being called for EXPLAIN
- When subquery is located in ORDER BY, EXPLAIN will run as follows:
select_describe() will run JOIN::prepare()/optimize() for the subquery;
then at some point subselect_single_select_engine::prepare() will be called,
which will create another join and run join->prepare().
In mainline mysql this is not a problem because subquery's join will be
destroyed after the first call.
In MariaDB, it won't (table elimination needs to keep JOIN objects around
for longer in order to know which tables were eliminated when constructing
EXPLAIN EXTENDED warning).
Fix the problem of memory leak by calling select_lex->cleanup() in
=== modified file 'sql/item_subselect.cc'
--- a/sql/item_subselect.cc 2010-03-09 15:03:54 +0000
+++ b/sql/item_subselect.cc 2010-03-09 19:29:05 +0000
@@ -1776,6 +1776,10 @@ int subselect_single_select_engine::prep
+ if (select_lex->join)
join= new JOIN(thd, select_lex->item_list,
select_lex->options | SELECT_NO_UNLOCK, result);
if (!join || !result)