Added a test case for LP bug #915291.

The bug was fixed by the patch for bug 914560. 

mysql-test/r/innodb_ext_key.result

@@ -585,5 +585,26 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 2	MATERIALIZED	s2	ALL	NULL	NULL	NULL	NULL	2	Using join buffer (flat, BNL join)
 DROP TABLE t1;
 set optimizer_switch=@save_optimizer_switch;
+#
+# LP Bug #915291: query using a materialized view
+#                 + extended_keys = on
+# (valgrinf complains fixed by the patch for bug #914560)
+#
+set @save_optimizer_switch=@@optimizer_switch;
+SET optimizer_switch = 'derived_with_keys=on';
+SET optimizer_switch = 'extended_keys=on';
+CREATE TABLE t1 (a varchar(1)) ENGINE=MyISAM;
+INSERT INTO t1 VALUES ('j'), ('v');
+CREATE TABLE t2 (b varchar(1)) ENGINE=MyISAM;
+INSERT INTO t2 VALUES ('j'), ('v');
+CREATE TABLE t3 (c varchar(1));
+INSERT INTO t2 VALUES ('m'), ('n');
+CREATE VIEW v
+AS SELECT DISTINCT * FROM t2 STRAIGHT_JOIN t3;
+SELECT * FROM t1, v WHERE a = b;
+a	b	c
+DROP VIEW v;
+DROP TABLE t1,t2,t3;
+set optimizer_switch=@save_optimizer_switch;
 set optimizer_switch=@save_ext_key_optimizer_switch;
 SET SESSION STORAGE_ENGINE=DEFAULT;

mysql-test/t/innodb_ext_key.test

@@ -312,5 +312,35 @@ DROP TABLE t1;
 
 set optimizer_switch=@save_optimizer_switch;
 
+--echo #
+--echo # LP Bug #915291: query using a materialized view
+--echo #                 + extended_keys = on
+--echo # (valgrinf complains fixed by the patch for bug #914560)
+--echo #
+
+set @save_optimizer_switch=@@optimizer_switch;
+
+SET optimizer_switch = 'derived_with_keys=on';
+SET optimizer_switch = 'extended_keys=on';
+
+CREATE TABLE t1 (a varchar(1)) ENGINE=MyISAM;
+INSERT INTO t1 VALUES ('j'), ('v');
+
+CREATE TABLE t2 (b varchar(1)) ENGINE=MyISAM;
+INSERT INTO t2 VALUES ('j'), ('v');
+
+CREATE TABLE t3 (c varchar(1));
+INSERT INTO t2 VALUES ('m'), ('n');
+
+CREATE VIEW v
+  AS SELECT DISTINCT * FROM t2 STRAIGHT_JOIN t3;
+
+SELECT * FROM t1, v WHERE a = b;
+
+DROP VIEW v;
+DROP TABLE t1,t2,t3;
+
+set optimizer_switch=@save_optimizer_switch;
+
 set optimizer_switch=@save_ext_key_optimizer_switch;
 SET SESSION STORAGE_ENGINE=DEFAULT;