Bug #1281 Wrong timestamp value

Description:
I don't know if this is a bug ?

create database test2;
connect test2;
create table test_table (c_in timestamp, c_out timestamp);
insert into test_table (c_in) values (null);
select * from test_table;

/*RESULT
+----------------+----------------+
| c_in           | c_out          |
+----------------+----------------+
| 20030915211420 | 00000000000000 |
+----------------+----------------+
1 row in set (0.01 sec)
*/

update test_table set c_out=null;
select * from test_table;

/*RESULT
+----------------+----------------+
| c_in           | c_out          |
+----------------+----------------+
| 20030915211528 | 20030915211528 |
+----------------+----------------+
1 row in set (0.01 sec)
*/

Why is c_in updated ???

/Per

How to repeat:
See above

Thank you for taking the time to write to us, but this is not
a bug. Please double-check the documentation available at
http://www.mysql.com/documentation/ and the instructions on
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