MDEV-24910 Crash with SELECT that uses table value constructor as a subselect

This bug caused crashes of the server when processing queries with table
value constructors (TVC) that contained subqueries and were used itself as
subselects. For such TVCs the following transformation is applied at the
prepare stage:
  VALUES (v1), ... (vn) => SELECT * FROM (VALUES (v1), ... (vn)) tvc_x.
This transformation allows to reduce the problem of evaluation of TVCs used
as subselects to the problem of evaluation of regular subselects.
The transformation is implemented in the wrap_tvc(). The code the function
to mimic the behaviour of the parser when processing the result of the
transformation. However this imitation was not free of some flaws. First
the function called the method exclude() that completely destroyed the
select tree structures below the transformed TVC. Second the function
used the procedure mysql_new_select to create st_select_lex nodes for
both wrapping select of the transformation and TVC. This also led to
constructing of invalid select tree structures.
The patch actually re-engineers the code of wrap_tvc().

Approved by Oleksandr Byelkin <sanja@mariadb.com>

1 files changed, 57 insertions, 0 deletions

diff --git a/mysql-test/main/table_value_constr.test b/mysql-test/main/table_value_constr.test
index 0a78fd9b386..2246a19d306 100644
--- a/mysql-test/main/table_value_constr.test
+++ b/mysql-test/main/table_value_constr.test
@@ -1459,4 +1459,61 @@ eval explain $q3;
 
 drop table t1;
 
+--echo #
+--echo # MDEV-24910: TVC containing subquery used as a subselect
+--echo #
+
+create table t1 (a int) engine=myisam;
+insert into t1 values (3), (7), (1);
+create table t2 (b int) engine=myisam;
+insert into t2 values (1), (2);
+
+let $q1=
+select (values ((select 2))) from t2;
+eval $q1;
+eval explain $q1;
+eval prepare stmt from "$q1";
+execute stmt;
+execute stmt;
+deallocate prepare stmt;
+
+let $q2=
+select (values ((select * from t1 where a > 10))) from t2;
+eval $q2;
+eval explain $q2;
+eval prepare stmt from "$q2";
+execute stmt;
+execute stmt;
+deallocate prepare stmt;
+
+create table t3 (a int);
+insert into t3 values
+ (3), (7), (7), (1), (3), (9), (7), (9), (8), (7), (8);
+
+create view v1 as select count(a) as c from t3 group by a;
+
+let $q3=
+select
+(values ((select * from t3 where a in (select * from v1))));
+eval $q3;
+eval explain $q3;
+eval prepare stmt from "$q3";
+execute stmt;
+execute stmt;
+deallocate prepare stmt;
+
+let $q4=
+select
+(values ((select * from t3
+          where a > 10 and a in (select * from v1))));
+eval $q4;
+eval explain $q4;
+eval prepare stmt from "$q4";
+execute stmt;
+execute stmt;
+deallocate prepare stmt;
+
+drop view v1;
+drop table t1,t2,t3;
+
 --echo End of 10.3 tests