--source include/have_innodb.inc

create table t1(f1 int not null, index(f1))engine=innodb;

create table t2(f1 int not null,

foreign key(f1) references t1(f1))engine=innodb;

alter table t1 rename to tm1, algorithm=copy;

show create table tm1;

Table	Create Table

tm1	CREATE TABLE `tm1` (

  `f1` int(11) NOT NULL,

  KEY `f1` (`f1`)

) ENGINE=InnoDB DEFAULT CHARSET=latin1

show create table t2;

Table	Create Table

t2	CREATE TABLE `t2` (

  `f1` int(11) NOT NULL,

  KEY `f1` (`f1`),

  CONSTRAINT `t2_ibfk_1` FOREIGN KEY (`f1`) REFERENCES `t1` (`f1`)

) ENGINE=InnoDB DEFAULT CHARSET=latin1

select * from information_schema.innodb_sys_foreign;

ID	FOR_NAME	REF_NAME	N_COLS	TYPE

test/t2_ibfk_1	test/t2	test/t1	1	0

create table t1(f1 int not null)engine=innodb;

Error failed: 1215: Cannot add foreign key constraint