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| author | Sergey Glukhov <Sergey.Glukhov@sun.com> | 2010-10-01 14:08:38 +0400 |
|---|---|---|
| committer | Sergey Glukhov <Sergey.Glukhov@sun.com> | 2010-10-01 14:08:38 +0400 |
| commit | 233e4d809aeccff150494b8632abedb77c213fbd (patch) | |
| tree | dd6a64f3ae4c4989c2ade7f0039d1143653ff241 /sql/item_subselect.cc | |
| parent | b76277fce5a375b931ae2f967e26956539eb1ffc (diff) | |
| download | mariadb-git-233e4d809aeccff150494b8632abedb77c213fbd.tar.gz | |
Bug#54488 crash when using explain and prepared statements with subqueries
The crash happens because original join table is replaced with temporary table
at execution stage and later we attempt to use this temporary table in
select_describe. It might happen that
Item_subselect::update_used_tables() method which sets const_item flag
is not called by some reasons (no where/having conditon in subquery for example).
It prevents JOIN::join_tmp creation and breaks original join.
The fix is to call ::update_used_tables() before ::const_item() check.
mysql-test/r/ps.result:
test case
mysql-test/t/ps.test:
test case
sql/item_subselect.cc:
call ::update_used_tables() before ::const_item() check.
Diffstat (limited to 'sql/item_subselect.cc')
| -rw-r--r-- | sql/item_subselect.cc | 26 |
1 files changed, 15 insertions, 11 deletions
diff --git a/sql/item_subselect.cc b/sql/item_subselect.cc index b93ea6f241b..2daeeb12b6d 100644 --- a/sql/item_subselect.cc +++ b/sql/item_subselect.cc @@ -1914,18 +1914,22 @@ int subselect_single_select_engine::exec() } if (!select_lex->uncacheable && thd->lex->describe && !(join->select_options & SELECT_DESCRIBE) && - join->need_tmp && item->const_item()) + join->need_tmp) { - /* - Force join->join_tmp creation, because this subquery will be replaced - by a simple select from the materialization temp table by optimize() - called by EXPLAIN and we need to preserve the initial query structure - so we can display it. - */ - select_lex->uncacheable|= UNCACHEABLE_EXPLAIN; - select_lex->master_unit()->uncacheable|= UNCACHEABLE_EXPLAIN; - if (join->init_save_join_tab()) - DBUG_RETURN(1); /* purecov: inspected */ + item->update_used_tables(); + if (item->const_item()) + { + /* + Force join->join_tmp creation, because this subquery will be replaced + by a simple select from the materialization temp table by optimize() + called by EXPLAIN and we need to preserve the initial query structure + so we can display it. + */ + select_lex->uncacheable|= UNCACHEABLE_EXPLAIN; + select_lex->master_unit()->uncacheable|= UNCACHEABLE_EXPLAIN; + if (join->init_save_join_tab()) + DBUG_RETURN(1); /* purecov: inspected */ + } } if (item->engine_changed) { |