#create a user with no privileges
create user 'test_user'@'localhost';
create user 'test_role1'@'';
#manualy create role
update mysql.user set is_role='Y' where user='test_role1';
insert into mysql.roles_mapping (HostFk, UserFk, RoleFk) values ('localhost',
                                                                 'test_user',
                                                                 'test_role1');
create user 'test_role2'@'';
#manualy create role
update mysql.user set is_role='Y' where user='test_role2';
insert into mysql.roles_mapping (HostFk, UserFk, RoleFk) values ('',
                                                                 'test_role1',
                                                                 'test_role2');
flush privileges;

use mysql;
--sorted_result
select * from roles_mapping;

#regular user rename
rename user 'test_user'@'localhost' to 'test_user_rm'@'newhost';
--sorted_result
select user, host from user where user like 'test%';
--sorted_result
select * from roles_mapping;

rename user 'test_role2'@'' to 'test_role2_rm'@'';
--sorted_result
select user, host from user where user like 'test%';
--sorted_result
select * from roles_mapping;

#role rename
rename user 'test_role1'@'' to 'test_role1_rm'@'';
--sorted_result
select user, host from user where user like 'test%';
--sorted_result
select * from roles_mapping;

delete from mysql.roles_mapping;
delete from mysql.user where user like 'test%';
flush privileges;