Queries against spider tables return wrong values for columns following constant declarations.

CREATE TABLE simple (

id int(10) unsigned NOT NULL AUTO_INCREMENT,  

val int(10) unsigned DEFAULT NULL, 

PRIMARY KEY (id),   ENGINE=InnoDB;

insert into simple(val) values(1);

create server s31689 foreign data wrapper mysql options (

host '10.0.0.241' ,

database 'd31689' ,

user 'spider' ,

password 'spider' ,

port 3306 );

CREATE TABLE simple (

id int(10) unsigned NOT NULL AUTO_INCREMENT,  

val int(10) unsigned DEFAULT NULL, 

PRIMARY KEY (id),   ENGINE=SPIDER 

DEFAULT CHARSET=utf8

COMMENT='srv "s31689", table "simple"'

Query OK, 0 rows affected (0.026 sec)

MariaDB [d31689]> select * from simple;

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

| id | val  |

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

|  1 |    1 |

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

1 row in set (0.015 sec)

MariaDB [d31689]> select id, 0 as const, val from simple;

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

| id | const | val  |

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

|  1 |     0 |    0 |

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

1 row in set (0.002 sec)