view with ifnull around window function error

create table t1(dt datetime);

insert into t1 values ('2017-05-17'), ('2017-05-18');

create view v1 as select dt, lead(dt) over (order by dt) from t1;

create view v2 as select dt, ifnull(lead(dt) over (order by dt), '9999-12-31 12:00:00') from t1;

select * from v1;

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

| dt                  | lead(dt) over (order by dt) |

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

| 2017-05-17 00:00:00 | 2017-05-18 00:00:00         |

| 2017-05-18 00:00:00 | NULL                        |

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

2 rows in set (0.00 sec)

select * from v2;

ERROR 1356 (HY000): View 'genesis.v2' references invalid table(s) or column(s) or function(s) or definer/invoker of view lack rights to use them

select dt, ifnull(lead(dt) over (order by dt), '9999-12-31 12:00:00') from t1;

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

| dt                  | ifnull(lead(dt) over (order by dt), '9999-12-31 12:00:00') |

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

| 2017-05-17 00:00:00 | 2017-05-18 00:00:00                                        |

| 2017-05-18 00:00:00 | 9999-12-31 12:00:00                                        |

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

2 rows in set (0.00 sec)