Wrong data types when mixing an utf8 *TEXT column and a short binary

CREATE OR REPLACE TABLE t1 (

  c_tinytext tinytext,

  c_text text,

  c_mediumtext mediumtext,

  c_longtext longtext

) CHARACTER SET utf8mb4;

CREATE OR REPLACE TABLE t2 AS SELECT

  COALESCE(c_tinytext,   CAST('binary data' AS BINARY)) AS mix_tinytext_binary,

  COALESCE(c_text,       CAST('binary data' AS BINARY)) AS mix_text_binary,

  COALESCE(c_mediumtext, CAST('binary data' AS BINARY)) AS mix_mediumtext_binary,

  COALESCE(c_longtext, CAST('binary data' AS BINARY)) AS mix_longtext_binary

FROM t1;

SHOW CREATE TABLE t2;

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

| Table | Create Table                                                                                                                                                                                                                                                                     |

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

| t2    | CREATE TABLE `t2` (

  `mix_tinytext_binary` blob DEFAULT NULL,

  `mix_text_binary` mediumblob DEFAULT NULL,

  `mix_mediumtext_binary` longblob DEFAULT NULL,

  `mix_longtext_binary` longblob DEFAULT NULL

) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci |

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

CREATE OR REPLACE TABLE t2 AS SELECT

  c_tinytext   AS mix_tinytext_binary,

  c_text       AS mix_text_binary,

  c_mediumtext AS mix_mediumtext_binary,

  c_longtext   AS mix_longtext_binary

FROM t1

UNION SELECT

  CAST('binary data' AS BINARY),

  CAST('binary data' AS BINARY),

  CAST('binary data' AS BINARY),

  CAST('binary data' AS BINARY);

SHOW CREATE TABLE t2;