MDEV-14862: Server crashes in Bitmap<64u>::merge / add_key_fieldbb-10.0-MDEV-14862

It is backport of MySQL fix:

Bug #19434916: FATAL_SIGNAL IN ADD_KEY_EQUAL_FIELDS() WITH
               UPDATE VIEW USING OUTER SUBQUERY

Issue:
-----
While resolving a column which refers to a table/view in an
outer query, it's respecitve item object is marked with the
outer query's select_lex object. But when the column refers
to a view or if the column is part of a subquery in the
HAVING clause, an Item_ref object is created. While the
reference to the outer query is stored by the Item_ref
object, the same is not stored in it's real_item.

This creates a problem with the IN-TO-EXISTS optmization.
When there is an index over the column in the inner query,
it will be considered since the column's real_item object
will be mistaken for a local field. This will lead to a
crash.

SOLUTION:
---------
Under the current design, the only way to fix this issue is
to check the reginfo.join_tab for a NULL value. If yes, the
query should not be worrying about the key use.

The testcase and comments added as part of the fix for
Bug#17766653 have been backported.

1 files changed, 12 insertions, 0 deletions

diff --git a/mysql-test/t/update_innodb.test b/mysql-test/t/update_innodb.test
index 67c356c4e2e..4ea321a60d2 100644
--- a/mysql-test/t/update_innodb.test
+++ b/mysql-test/t/update_innodb.test
@@ -37,3 +37,15 @@ UPDATE t1 a JOIN t2 b ON a.c1 = b.c1 JOIN v1 vw ON b.c2 = vw.c1 JOIN t3 del ON v
 
 drop view v1;
 drop table t1,t2,t3,t4;
+
+--echo #
+--echo # MDEV-14862: Server crashes in Bitmap<64u>::merge / add_key_field
+--echo #
+
+CREATE TABLE t1 (a INT) ENGINE=InnoDB;
+CREATE VIEW v1 AS SELECT * FROM t1;
+CREATE TABLE t2 (b INT) ENGINE=InnoDB;
+DELETE FROM v1 WHERE a IN ( SELECT a FROM t2 );
+
+drop view v1;
+drop table t1,t2;