Wrong result with LEFT/RIGHT joins on constant tables

CREATE TABLE t1 (a INT) ENGINE=MyISAM;

INSERT INTO t1 VALUES (10);

CREATE TABLE t2 (pk INT, b INT, PRIMARY KEY(pk), KEY(b)) ENGINE=MyISAM;

CREATE VIEW v2 AS SELECT * FROM t2;

CREATE TABLE t3 (c INT, KEY(c)) ENGINE=MyISAM;

INSERT INTO t3 VALUES (1),(2);

SELECT * FROM t1 LEFT JOIN v2 RIGHT JOIN t3 ON b = c ON a = c;

ALTER TABLE t3 DISABLE KEYS;

SELECT * FROM t1 LEFT JOIN v2 RIGHT JOIN t3 ON b = c ON a = c;

MariaDB [test]> SELECT * FROM t1 LEFT JOIN v2 RIGHT JOIN t3 ON b = c ON a = c;

Empty set (0.002 sec)

MariaDB [test]> ALTER TABLE t3 DISABLE KEYS;

Query OK, 0 rows affected (0.001 sec)

MariaDB [test]> SELECT * FROM t1 LEFT JOIN v2 RIGHT JOIN t3 ON b = c ON a = c;

+------+------+------+------+

| a    | pk   | b    | c    |

+------+------+------+------+

|   10 | NULL | NULL |    1 |

|   10 | NULL | NULL |    2 |

+------+------+------+------+

2 rows in set (0.003 sec)

MariaDB [test]> SELECT * FROM t1 LEFT JOIN v2 RIGHT JOIN t3 ON b = c ON a = c;

+------+------+------+------+

| a    | pk   | b    | c    |

+------+------+------+------+

|   10 | NULL | NULL | NULL |

+------+------+------+------+

1 row in set (0.002 sec)

commit 658128af43b4d7c6db445164f8ed25ed4d1e3109

Author: Igor Babaev

Date:   Sun Feb 3 14:56:12 2019 -0800

    MDEV-16188 Use in-memory PK filters built from range index scans