Seemingly different result upon aggregate function on BIT column directly vs subquery

CREATE TABLE t (b BIT);

INSERT INTO t VALUES (0);

SELECT MIN(b) AS f FROM t;

SELECT f FROM (SELECT MIN(b) AS f FROM t) sq;

# Cleanup

DROP TABLE t;

MariaDB [test]> SELECT MIN(b) AS f FROM t;

+------+

| f    |

+------+

| 0    |

+------+

1 row in set (0.001 sec)

MariaDB [test]> SELECT f FROM (SELECT MIN(b) AS f FROM t) sq;

+------+

| f    |

+------+

|      |

+------+

1 row in set (0.001 sec)

MariaDB [test]> SELECT MIN(b) AS f FROM t;

Field   1:  `f`

Catalog:    `def`

Database:   ``

Table:      ``

Org_table:  ``

Type:       BIT

Collation:  binary (63)

Length:     1

Max_length: 1

Decimals:   0

Flags:      UNSIGNED BINARY 

+------+

| f    |

+------+

| 0    |

+------+

1 row in set (0.001 sec)

MariaDB [test]> SELECT f FROM (SELECT MIN(b) AS f FROM t) sq;

Field   1:  `f`

Catalog:    `def`

Database:   ``

Table:      `sq`

Org_table:  `t`

Type:       BIT

Collation:  binary (63)

Length:     1

Max_length: 1

Decimals:   0

Flags:      UNSIGNED