MDEV-7260: Crash in get_best_combination when executing multi-table UPDATE with nested views

Do not use merge_for_insert for commands which use SELECT because optimizer can't work with such tables.

Fixes which makes multi-delete working with normally merged views.

1 files changed, 13 insertions, 0 deletions

diff --git a/mysql-test/r/view.result b/mysql-test/r/view.result
index cb40fbbcbca..b3977648d41 100644
--- a/mysql-test/r/view.result
+++ b/mysql-test/r/view.result
@@ -5398,6 +5398,19 @@ DROP VIEW v1;
 DROP TABLE t1, t2;
 create view v1 as select 1;
 drop view v1;
+#
+# MDEV-7260: Crash in get_best_combination when executing multi-table
+# UPDATE with nested views
+#
+CREATE TABLE `t1` (`id` bigint(20));
+INSERT INTO `t1` VALUES (1),(2);
+CREATE TABLE `t2` (`id` bigint(20));
+CREATE TABLE `t3` (`id` bigint(20), `flag` tinyint(4));
+create view v1 as select id from t1;
+create view v2 as select t2.* from (t2 left join v1 using (id));
+update t3 left join v2 using (id) set flag=flag+1;
+drop view v2, v1;
+drop table t1, t2, t3;
 # -----------------------------------------------------------------
 # -- End of 5.5 tests.
 # -----------------------------------------------------------------