Query returns wrong result when using split optimization

--source include/have_innodb.inc

CREATE TABLE raw_a (

  date varchar(100),

  v varchar(100),

  c char(5),

  foo bigint(20)

) ENGINE=InnoDB;

INSERT INTO raw_a VALUES ('20211231','A','bh',1),('20211231','B','bh',0),('20211231','C','bh',0),('20211231','D','bh',0),('20211231','E','bh',0),('20211231','G','bh',0),('20211231','H','bh',0),('20211231','I','bh',3),('20211231','J','bh',0),('20211231','K','bh',0),('20211231','A','bl',9),('20211231','B','bl',0),('20211231','C','bl',0),('20211231','D','bl',0),('20211231','E','bl',0),('20211231','G','bl',0),('20211231','H','bl',0),('20211231','I','bl',7),('20211231','J','bl',0),('20211231','K','bl',0),('20211231','M','bl',0),('20211231','N','bl',3),('20211231','R','bl',9),('20211231','S','bl',0),('20211231','T','bl',0),('20211231','U','bl',0),('20211231','V','bl',0);

CREATE TABLE raw_b (

  date int(11) NOT NULL,

  v varchar(50),

  t varchar(512),

  c varchar(50),

  o varchar(10),

  sh varchar(10),

  p char(5),

  s varchar(20),

  foo bigint(20),

  PRIMARY KEY (date,v,t,c,o,sh,p,s),

  KEY date (date,c,v)

) ENGINE=InnoDB;

INSERT INTO raw_b VALUES (20211231,'A','a','bl','a','f','0','[0-5]',2),(20211231,'A','a','bl','a','f','0','[6-9)',2),(20211231,'A','b','bl','a','f','0','[0-5]',2),(20211231,'A','b','bl','a','f','0','[6-9)',2),(20211231,'A','c','bh','a','f','0','[0-5]',2),(20211231,'A','c','bh','a','f','0','[10-15)',2),(20211231,'A','c','bh','a','f','0','[15-20)',2),(20211231,'A','c','bh','a','f','0','[20-30)',2),(20211231,'A','c','bh','a','f','0','[6-9)',2),(20211231,'A','c','bl','a','f','0','[0-5]',2),(20211231,'A','c','bl','a','f','0','[20-30)',2),(20211231,'A','c','bl','a','f','0','[6-9)',2),(20211231,'A','cc','bl','a','f','0','[0-5]',2),(20211231,'A','cc','bl','a','f','0','[10-15)',2),(20211231,'A','cc','bl','a','f','0','[15-20)',2),(20211231,'A','cc','bl','a','f','0','[6-9)',2),(20211231,'A','cc','bl','a','LO','0','[0-5]',2),(20211231,'A','ccc','bl','a','f','0','[0-5]',2),(20211231,'A','d','bh','a','f','0','[0-5]',2),(20211231,'A','d','bh','a','f','0','[10-15)',2),(20211231,'A','d','bh','a','f','0','[20-30)',2),(20211231,'A','d','bh','a','f','0','[6-9)',2),(20211231,'A','e','bh','a','f','0','[0-5]',2),(20211231,'A','e','bh','a','f','0','[10-15)',2),(20211231,'A','e','bh','a','f','0','[20-30)',2),(20211231,'A','e','bh','a','f','0','[6-9)',2),(20211231,'A','f','bh','a','f','0','[6-9)',2),(20211231,'A','g','bh','a','f','0','[0-5]',2),(20211231,'A','g','bh','a','f','0','[10-15)',2),(20211231,'A','g','bh','a','f','0','[6-9)',2),(20211231,'A','h','bh','a','f','0','[0-5]',2),(20211231,'A','h','bh','a','f','0','[10-15)',2),(20211231,'A','h','bh','a','f','0','[15-20)',2),(20211231,'A','h','bh','a','f','0','[20-30)',2),(20211231,'A','h','bh','a','f','0','[30-inf)',2),(20211231,'A','h','bh','a','f','0','[6-9)',2),(20211231,'A','h','bh','a','f','1-4','[10-15)',2),(20211231,'A','h','bh','a','f','<0','[0-5]',2),(20211231,'A','i','bh','a','f','0','[0-5]',2),(20211231,'A','i','bh','a','f','0','[20-30)',2),(20211231,'A','i','bh','a','f','0','[6-9)',2),(20211231,'A','j','bh','a','f','0','[0-5]',2),(20211231,'A','j','bh','a','f','0','[6-9)',2),(20211231,'A','k','bh','a','f','0','[0-5]',2),(20211231,'A','k','bh','a','f','0','[10-15)',2),(20211231,'A','k','bh','a','f','0','[15-20)',2),(20211231,'A','k','bh','a','f','0','[20-30)',2),(20211231,'A','k','bh','a','f','0','[30-inf)',2),(20211231,'A','k','bh','a','f','0','[6-9)',2),(20211231,'A','l','bh','a','f','0','[0-5]',2),(20211231,'A','m','bh','a','f','0','[0-5]',2),(20211231,'A','m','bh','a','f','0','[10-15)',2),(20211231,'A','m','bh','a','f','0','[15-20)',2),(20211231,'A','m','bh','a','f','0','[20-30)',2),(20211231,'A','m','bh','a','f','0','[6-9)',2),(20211231,'A','m','bh','a','f','>4','[10-15)',2),(20211231,'A','n','bh','a','f','0','[0-5]',2),(20211231,'A','n','bl','a','f','0','[0-5]',2),(20211231,'A','o','bh','a','f','0','[0-5]',2),(20211231,'A','o','bh','a','f','0','[6-9)',2),(20211231,'A','p','bh','a','f','0','[0-5]',2),(20211231,'A','p','bh','a','f','0','[10-15)',2),(20211231,'A','p','bh','a','f','0','[15-20)',2),(20211231,'A','p','bh','a','f','0','[6-9)',2),(20211231,'A','p','bh','a','f','<0','[0-5]',2),(20211231,'Afdaskjlhfaslkjfhasdklfhdskla','j','bh','a','f','0','[0-5]',2),(20211231,'Afdaskjlhfaslkjfhasdklfhdskla','j','bh','a','f','0','[10-15)',2),(20211231,'Afdaskjlhfaslkjfhasdklfhdskla','j','bh','a','f','0','[15-20)',2),(20211231,'Afdaskjlhfaslkjfhasdklfhdskla','j','bh','a','f','0','[20-30)',2),(20211231,'Afdaskjlhfaslkjfhasdklfhdskla','j','bh','a','f','0','[30-inf)',2),(20211231,'Afdaskjlhfaslkjfhasdklfhdskla','j','bh','a','f','0','[6-9)',2);

SELECT a.date, a.c, b.foo, a.foo

    FROM

        (SELECT date,c,SUM(foo) as foo

         FROM raw_b

         WHERE date >= 20211231

         GROUP BY date,c

        ) as b,

        (SELECT date, c, SUM(foo) as foo

         FROM raw_a

         WHERE date >= 20211231

         GROUP BY date,c

        ) as a where a.date = b.date AND a.c = b.c;

 set optimizer_switch="split_materialized=off";

SELECT a.date, a.c, b.foo, a.foo

    FROM

        (SELECT date,c,SUM(foo) as foo

         FROM raw_b

         WHERE date >= 20211231

         GROUP BY date,c

        ) as b,

        (SELECT date, c, SUM(foo) as foo

         FROM raw_a

         WHERE date >= 20211231

         GROUP BY date,c

        ) as a where a.date = b.date AND a.c = b.c;

MariaDB [test]>  SELECT a.date, a.c, b.foo, a.foo     FROM         (SELECT date,c,SUM(foo) as foo          FROM raw_b          WHERE date >= 20211231          GROUP BY date,c         ) as b,         (SELECT date, c, SUM(foo) as foo          FROM raw_a          WHERE date >= 20211231          GROUP BY date,c         ) as a where a.date = b.date AND a.c = b.c;

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

| date     | c    | foo  | foo  |

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

| 20211231 | bl   |  142 |   28 |

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

1 row in set (0.016 sec)

MariaDB [test]> set optimizer_switch="split_materialized=off";

Query OK, 0 rows affected (0.001 sec)

MariaDB [test]>  SELECT a.date, a.c, b.foo, a.foo     FROM         (SELECT date,c,SUM(foo) as foo          FROM raw_b          WHERE date >= 20211231          GROUP BY date,c         ) as b,         (SELECT date, c, SUM(foo) as foo          FROM raw_a          WHERE date >= 20211231          GROUP BY date,c         ) as a where a.date = b.date AND a.c = b.c;

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

| date     | c    | foo  | foo  |

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

| 20211231 | bh   |  114 |    4 |

| 20211231 | bl   |   28 |   28 |

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

2 rows in set (0.008 sec)

MariaDB [test]> explain extended SELECT a.date, a.c, b.foo, a.foo     FROM         (SELECT date,c,SUM(foo) as foo          FROM raw_b          WHERE date >= 20211231          GROUP BY date,c         ) as b,         (SELECT date, c, SUM(foo) as foo          FROM raw_a          WHERE date >= 20211231          GROUP BY date,c         ) as a where a.date = b.date AND a.c = b.c;

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

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

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

|    1 | PRIMARY         | <derived3> | ALL  | NULL          | NULL    | NULL    | NULL       | 27   |   100.00 | Using where                                  |

|    1 | PRIMARY         | <derived2> | ref  | key0          | key0    | 56      | a.date,a.c | 2    |   100.00 | Using where                                  |

|    3 | DERIVED         | raw_a      | ALL  | NULL          | NULL    | NULL    | NULL       | 27   |   100.00 | Using where; Using temporary; Using filesort |

|    2 | LATERAL DERIVED | raw_b      | ref  | PRIMARY,date  | PRIMARY | 4       | a.date     | 1    |   100.00 | Using where; Using temporary; Using filesort |

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

4 rows in set, 1 warning (0.005 sec)

Note (Code 1003): /* select#1 */ select `a`.`date` AS `date`,`a`.`c` AS `c`,`b`.`foo` AS `foo`,`a`.`foo` AS `foo` from (/* select#2 */ select `test`.`raw_b`.`date` AS `date`,`test`.`raw_b`.`c` AS `c`,sum(`test`.`raw_b`.`foo`) AS `foo` from `test`.`raw_b` where `test`.`raw_b`.`date` >= 20211231 and `test`.`raw_b`.`date` = `a`.`date` and `test`.`raw_b`.`c` = `a`.`c` group by `test`.`raw_b`.`date`) `b` join (/* select#3 */ select `test`.`raw_a`.`date` AS `date`,`test`.`raw_a`.`c` AS `c`,sum(`test`.`raw_a`.`foo`) AS `foo` from `test`.`raw_a` where `test`.`raw_a`.`date` >= 20211231 group by `test`.`raw_a`.`date`,`test`.`raw_a`.`c`) `a` where `a`.`date` = `b`.`date` and `a`.`c` = `b`.`c`