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

Do not unwrap view references to keep table info.
(Row-IN subselect does not unwrap items so it does not need fix)

mysql-test/r/update_innodb.result

@@ -29,3 +29,13 @@ CREATE ALGORITHM=UNDEFINED VIEW `v1` AS select `t4`.`c1` AS `c1`,`t4`.`c2` AS `c
 UPDATE t1 a JOIN t2 b ON a.c1 = b.c1 JOIN v1 vw ON b.c2 = vw.c1 JOIN t3 del ON vw.c2 = del.c2 SET a.c2 = ( SELECT max(t.c1) FROM t3 t, v1 i WHERE del.c2 = t.c2 AND vw.c3 = i.c3 AND t.c3 = 4 ) WHERE a.c2 IS NULL OR a.c2 < '2011-05-01';
 drop view v1;
 drop table t1,t2,t3,t4;
+#
+# MDEV-14862: Server crashes in Bitmap<64u>::merge / add_key_field
+#
+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 );
+DELETE FROM v1 WHERE (a,a) IN ( SELECT a,a FROM t2 );
+drop view v1;
+drop table t1,t2;

mysql-test/t/update_innodb.test

@@ -37,3 +37,16 @@ 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 );
+DELETE FROM v1 WHERE (a,a) IN ( SELECT a,a FROM t2 );
+
+drop view v1;
+drop table t1,t2;

sql/item_subselect.cc

@@ -2070,7 +2070,10 @@ Item_in_subselect::create_single_in_to_exists_cond(JOIN *join,
   }
   else
   {
-    Item *item= (Item*) select_lex->item_list.head()->real_item();
+    Item *item= (Item*) select_lex->item_list.head();
+    if (item->type() != REF_ITEM ||
+        ((Item_ref*)item)->ref_type() != Item_ref::VIEW_REF)
+      item= item->real_item();
 
     if (select_lex->table_list.elements)
     {