Inconsistent warnings when inserting a DATETIME-alike data into a TIME column

mysql> DROP TABLE IF EXISTS t1;

Query OK, 0 rows affected (0.03 sec)

mysql> CREATE TABLE t1 (from_str TIME, from_int TIME,from_dec TIME, from_double TIME);

Query OK, 0 rows affected (0.15 sec)

mysql> INSERT INTO t1 VALUES ('2001-01-01 10:20:30',20010101102030,20010101102030.0,20010101102030e0);

Query OK, 1 row affected, 4 warnings (0.01 sec)

mysql> SHOW WARNINGS;

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

| Level   | Code | Message                                          |

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

| Note    | 1265 | Data truncated for column 'from_str' at row 1    |

| Warning | 1265 | Data truncated for column 'from_int' at row 1    |

| Warning | 1265 | Data truncated for column 'from_dec' at row 1    |

| Warning | 1265 | Data truncated for column 'from_double' at row 1 |

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

4 rows in set (0.00 sec)

mysql> SELECT * FROM t1;

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

| from_str | from_int | from_dec | from_double |

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

| 10:20:30 | 10:20:30 | 10:20:30 | 10:20:30    |

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

1 row in set (0.00 sec)