Dynamic CREATE TABLE does not preserve the data type of SP variables with NULL value

DELIMITER $$

BEGIN NOT ATOMIC

  DECLARE d0 DATETIME DEFAULT NULL;

  DECLARE d1 DATETIME DEFAULT '2001-01-01 00:00:00';

  DECLARE i0 INT DEFAULT NULL;

  DECLARE i1 INT DEFAULT 10;

  PREPARE stmt FROM 'CREATE OR REPLACE TABLE t1 AS SELECT ? AS c1,? AS c2,? AS c3,? AS c4';

  EXECUTE stmt USING d0,d1,i0,i1;

  DEALLOCATE PREPARE stmt;

  SHOW CREATE TABLE t1;

END;

$$

DELIMITER ;

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

| Table | Create Table                                                                                                                                                                      |

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

| t1    | CREATE TABLE `t1` (

  `c1` binary(0) DEFAULT NULL,

  `c2` datetime DEFAULT NULL,

  `c3` binary(0) DEFAULT NULL,

  `c4` bigint(21) NOT NULL

) ENGINE=InnoDB DEFAULT CHARSET=latin1 |

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