Wrong result for CONCAT(GREATEST(TIME('00:00:01'),TIME('00:00:00')))

This query:

SELECT CONCAT(GREATEST(TIME('00:00:01'),TIME('00:00:00')));

returns "0000-00-00 00:00:01.000000".

The expected result is "00:00:01.000000".

Note,

SELECT GREATEST(TIME('00:00:01'),TIME('00:00:00'));

works fine and returns "00:00:01.000000".

MySQL-5.5 and MySQL-5.6 are not affected.