No 'Impossible WHERE' message after pushdown when OR cond is used

CREATE TABLE t1(a INT, b INT, c INT);

INSERT INTO t1 VALUES (1,14,3), (2,13,2), (1,22,1), (3,13,4), (3,14,2);

SELECT t1.a,MAX(t1.b),t1.c

FROM t1

WHERE (t1.a = 1) OR (t1.a = 3)

GROUP BY t1.a

HAVING (t1.a = 2);

SELECT t1.a,MAX(t1.b),t1.c

FROM t1

WHERE ((t1.a = 1) OR (t1.a = 3)) AND (t1.a = 2)

GROUP BY t1.a;

MariaDB [test]> SELECT t1.a,MAX(t1.b),t1.c FROM t1 WHERE (t1.a = 1) OR (t1.a = 3) GROUP BY t1.a HAVING (t1.a = 2);

Empty set (0.001 sec)

MariaDB [test]> explain format=json SELECT t1.a,MAX(t1.b),t1.c FROM t1 WHERE (t1.a = 1) OR (t1.a = 3) GROUP BY t1.a HAVING (t1.a = 2);

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

| EXPLAIN                                                                                                                                                                                                                             |

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

| {

  "query_block": {

    "select_id": 1,

    "table": {

      "table_name": "t1",

      "access_type": "ALL",

      "rows": 3,

      "filtered": 100,

      "attached_condition": "t1.a = 2 and (t1.a = 1 or t1.a = 3)"

    }

  }

} |

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

1 row in set (0.002 sec)

MariaDB [test]> SELECT t1.a,MAX(t1.b),t1.c

    -> FROM t1

    -> WHERE ((t1.a = 1) OR (t1.a = 3)) AND (t1.a = 2)

    -> GROUP BY t1.a;

Empty set (0.001 sec)

MariaDB [test]> explain format=json SELECT t1.a,MAX(t1.b),t1.c

    -> FROM t1

    -> WHERE ((t1.a = 1) OR (t1.a = 3)) AND (t1.a = 2)

    -> GROUP BY t1.a;

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

| EXPLAIN                                                                                                 |

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

| {

  "query_block": {

    "select_id": 1,

    "table": {

      "message": "Impossible WHERE"

    }

  }

} |

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

1 row in set (0.001 sec)