--source include/have_innodb.inc

create table a(id varchar(1) character set utf8mb4, primary key(id));
--error 1005,1215
create table b(id varchar(1) character set utf8, b_id varchar(1) character set utf8, primary key(id), CONSTRAINT a_fkey FOREIGN KEY (b_id) REFERENCES a (id));
show warnings;

drop table a;