Fix for bug #18306: MySQL crashes and restarts using subquery

mysql-test/r/subselect.result:
  Fix for bug #18306: MySQL crashes and restarts using subquery
  test case
mysql-test/t/subselect.test:
  Fix for bug #18306: MySQL crashes and restarts using subquery
  test case
sql/opt_range.cc:
  Fix for bug #18306: MySQL crashes and restarts using subquery
  Restore thd->mem_root because
  during the cond->val_int() evaluation we can come across a subselect 
  item which may allocate memory on the thd->mem_root and assumes
  all the memory allocated has the same life span as the subselect
  item itself.

1 files changed, 11 insertions, 0 deletions

diff --git a/mysql-test/t/subselect.test b/mysql-test/t/subselect.test
index 368020dd721..1ef80bdd7ac 100644
--- a/mysql-test/t/subselect.test
+++ b/mysql-test/t/subselect.test
@@ -2074,3 +2074,14 @@ create table t1( f1 int,f2 int);
 insert into t1 values (1,1),(2,2);
 select tt.t from (select 'crash1' as t, f2 from t1) as tt left join t1 on tt.t = 'crash2' and tt.f2 = t1.f2 where tt.t = 'crash1';
 drop table t1;
+
+#
+# Bug #18306: server crash on delete using subquery.
+#
+
+create table t1 (c int, key(c));                              
+insert into t1 values (1142477582), (1142455969);
+create table t2 (a int, b int);
+insert into t2 values (2, 1), (1, 0);
+delete from t1 where c <= 1140006215 and (select b from t2 where a = 2) = 1;
+drop table t1, t2;