Support partitioning for underlying MERGE tables

CREATE DATABASE FOO;

USE FOO;

CREATE TABLE `Archive` (

  `event_id` bigint(20) unsigned NOT NULL AUTO_INCREMENT,

  `alarmed` datetime DEFAULT NULL,

  PRIMARY KEY (`event_id`, `alarmed`)

) ENGINE=MyISAM DEFAULT CHARSET=latin1

/*!50100 PARTITION BY RANGE (TO_DAYS(alarmed))

(PARTITION p_2015_12 VALUES LESS THAN (736329) ENGINE = MyISAM,

PARTITION p_other VALUES LESS THAN MAXVALUE ENGINE = MyISAM) */;

CREATE DATABASE BAR;

USE BAR;

CREATE TABLE `Archive` (

  `event_id` bigint(20) unsigned NOT NULL AUTO_INCREMENT,

  `alarmed` datetime DEFAULT NULL,

  PRIMARY KEY (`event_id`, `alarmed`)

) ENGINE=MyISAM DEFAULT CHARSET=latin1

/*!50100 PARTITION BY RANGE (TO_DAYS(alarmed))

(PARTITION p_2015_12 VALUES LESS THAN (736329) ENGINE = MyISAM,

PARTITION p_other VALUES LESS THAN MAXVALUE ENGINE = MyISAM) */;

CREATE DATABASE BAZ;

USE BAZ;

CREATE TABLE `Archive` (

  `event_id` bigint(20) unsigned NOT NULL AUTO_INCREMENT,

  `alarmed` datetime DEFAULT NULL,

  PRIMARY KEY (`event_id`, `alarmed`)

) ENGINE=MERGE UNION(`FOO`.`History`,`BAR`.`History`);

mysql> select * from Archive;

ERROR 1168 (HY000): Unable to open underlying table which is differently defined or of non-MyISAM type or doesn't exist