--source include/have_innodb.inc

CREATE TABLE t1 (
  `i1` INT(10) UNSIGNED NOT NULL,
  `d1` TIMESTAMP NULL DEFAULT NULL
) ENGINE=innodb;

show create table t1;

INSERT INTO t1 (i1) VALUES (1), (2), (3), (4), (5);
select * from t1;
set sql_mode = 'STRICT_ALL_TABLES,NO_ZERO_DATE';
ALTER TABLE t1 CHANGE `d1` `d1` TIMESTAMP DEFAULT CURRENT_TIMESTAMP  NOT NULL;
drop table t1;

CREATE TABLE t1 (
  `i1` INT(10) UNSIGNED NOT NULL,
  `d1` TIMESTAMP NULL DEFAULT NULL
) ENGINE=innodb;
INSERT INTO t1 (i1) VALUES (1), (2), (3), (4), (5);
ALTER TABLE t1 CHANGE `d1` `d1` TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP;
drop table t1;
set sql_mode = '';