diff options
| -rw-r--r-- | mysql-test/r/union.result | 20 | ||||
| -rw-r--r-- | mysql-test/t/union.test | 20 | ||||
| -rw-r--r-- | sql/sql_union.cc | 24 |
3 files changed, 52 insertions, 12 deletions
diff --git a/mysql-test/r/union.result b/mysql-test/r/union.result index 4ecac34d9fa..40f5a77e3d0 100644 --- a/mysql-test/r/union.result +++ b/mysql-test/r/union.result @@ -1935,3 +1935,23 @@ id select_type table type possible_keys key key_len ref rows Extra 3 UNION t1 ALL NULL NULL NULL NULL 4 NULL UNION RESULT <union2,3> ALL NULL NULL NULL NULL NULL drop table t1; +# +# MDEV-6868:MariaDB server crash ( select with union and order by +# with subquery ) +# +CREATE TABLE t1 ( id INTEGER, sample_name1 VARCHAR(100), sample_name2 VARCHAR(100), PRIMARY KEY(id) ); +INSERT INTO t1 ( id, sample_name1, sample_name2 ) VALUES ( 1, 'aaaa', 'bbbb' ), ( 2, 'cccc', 'dddd' ); +( +SELECT sample_name1 AS testname FROM t1 +) +UNION +( +SELECT sample_name2 AS testname FROM t1 C ORDER BY (SELECT T.sample_name1 FROM t1 T WHERE T.id = C.id) +) +; +testname +aaaa +cccc +bbbb +dddd +drop table t1; diff --git a/mysql-test/t/union.test b/mysql-test/t/union.test index a5d7dae606f..9204ddd22e5 100644 --- a/mysql-test/t/union.test +++ b/mysql-test/t/union.test @@ -1330,3 +1330,23 @@ create table t1 (a int); insert t1 values (1),(2),(3),(1); explain select 1 from dual where exists (select max(a) from t1 group by a union select a+2 from t1); drop table t1; + +--echo # +--echo # MDEV-6868:MariaDB server crash ( select with union and order by +--echo # with subquery ) +--echo # + +CREATE TABLE t1 ( id INTEGER, sample_name1 VARCHAR(100), sample_name2 VARCHAR(100), PRIMARY KEY(id) ); + +INSERT INTO t1 ( id, sample_name1, sample_name2 ) VALUES ( 1, 'aaaa', 'bbbb' ), ( 2, 'cccc', 'dddd' ); + +( + SELECT sample_name1 AS testname FROM t1 +) +UNION +( + SELECT sample_name2 AS testname FROM t1 C ORDER BY (SELECT T.sample_name1 FROM t1 T WHERE T.id = C.id) +) +; + +drop table t1; diff --git a/sql/sql_union.cc b/sql/sql_union.cc index 1bbd2eb6c29..6e2e6e06ff7 100644 --- a/sql/sql_union.cc +++ b/sql/sql_union.cc @@ -315,18 +315,6 @@ bool st_select_lex_unit::prepare(THD *thd_arg, select_result *sel_result, can_skip_order_by= is_union_select && !(sl->braces && sl->explicit_limit); - /* - Remove all references from the select_lex_units to the subqueries that - are inside the ORDER BY clause. - */ - if (can_skip_order_by) - { - for (ORDER *ord= (ORDER *)sl->order_list.first; ord; ord= ord->next) - { - (*ord->item)->walk(&Item::eliminate_subselect_processor, FALSE, NULL); - } - } - saved_error= join->prepare(&sl->ref_pointer_array, sl->table_list.first, sl->with_wild, @@ -350,6 +338,18 @@ bool st_select_lex_unit::prepare(THD *thd_arg, select_result *sel_result, if (saved_error || (saved_error= thd_arg->is_fatal_error)) goto err; /* + Remove all references from the select_lex_units to the subqueries that + are inside the ORDER BY clause. + */ + if (can_skip_order_by) + { + for (ORDER *ord= (ORDER *)sl->order_list.first; ord; ord= ord->next) + { + (*ord->item)->walk(&Item::eliminate_subselect_processor, FALSE, NULL); + } + } + + /* Use items list of underlaid select for derived tables to preserve information about fields lengths and exact types */ |