create table bug53290 (x bigint) engine=innodb;
insert into bug53290 () values (),(),(),(),(),(),(),(),(),(),(),();
insert into bug53290 select * from bug53290;
insert into bug53290 select * from bug53290;
insert into bug53290 select * from bug53290;
insert into bug53290 select * from bug53290;
insert into bug53290 select * from bug53290;
insert into bug53290 select * from bug53290;
insert into bug53290 select * from bug53290;
insert into bug53290 select * from bug53290;
insert into bug53290 select * from bug53290;
insert into bug53290 select * from bug53290;
insert into bug53290 select * from bug53290;
insert into bug53290 select * from bug53290;
insert into bug53290 select * from bug53290;
alter table bug53290 add unique index `idx` (x);
drop table bug53290;