revision-id: c5975eaea174460e774e77717e972a8d32e6c8de (mariadb-5.5.56-38-gc5975eaea17)
parent(s): f305a7ce4bccbd56520d874e1d81a4f29bc17a96
author: Sergei Golubchik
committer: Sergei Golubchik
timestamp: 2017-07-12 10:39:02 +0200
message:
MDEV-7339 Server crashes in Item_func_trig_cond::val_int
Item_in_subselect::pushed_cond_guards[] array is allocated only when
left_expr->maybe_null. And it is used (for row expressions) when
left_expr->element_index(i)->maybe_null.
For left_expr being a multi-column subquery, its maybe_null is
always false when the subquery doesn't use tables (see
Item_singlerow_subselect::fix_length_and_dec()
and subselect_single_select_engine::fix_length_and_dec()),
otherwise it's always true.
But row elements can be NULL regardless, so let's always allocate
pushed_cond_guards for multi-column subqueries, no matter whether
its maybe_null was forced to true or false.
