Context replay fails for partitioned table with ucs2 data

set default_storage_engine=myisam;

create table t1 (a varchar(5) character set ucs2 collate ucs2_bin)

partition by range columns (a)

(partition p0 values less than (0x0041));

insert into t1 values (0x00410000);

select hex(a) from t1 where a like 'A_';

set optimizer_record_context=1;

select context into dumpfile '/tmp/1.sql' from information_schema.optimizer_context;

source /tmp/1.sql

MariaDB [test]> explain partitions select hex(a) from t1 where a like 'A_';

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

| id   | select_type | table | partitions | type   | possible_keys | key  | key_len | ref  | rows | Extra |

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

|    1 | SIMPLE      | t1    | p0         | system | NULL          | NULL | NULL    | NULL | 1    |       |

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

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

| id   | select_type | table | partitions | type | possible_keys | key  | key_len | ref  | rows | Extra                                               |

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

|    1 | SIMPLE      | NULL  | NULL       | NULL | NULL          | NULL | NULL    | NULL | NULL | Impossible WHERE noticed after reading const tables |

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