--enable_connect_log

alter table mysql.user modify User char(80) binary not null default '';
alter table mysql.db modify User char(80) binary not null default '';
alter table mysql.tables_priv modify User char(80) binary not null default '';
alter table mysql.columns_priv modify User char(80) binary not null default '';
alter table mysql.procs_priv modify User char(80) binary not null default '';
alter table mysql.proc modify definer char(141) collate utf8_bin not null default '';
alter table mysql.event modify definer char(141) collate utf8_bin not null default '';
flush privileges;

create user 'a123456789-123456789-123456789-123456789-123456789-123456789-123456789-123456789'@'localhost';

--connect (con1,localhost,a123456789-123456789-123456789-123456789-123456789-123456789-123456789-123456789,,)
--error ER_DBACCESS_DENIED_ERROR
create database db;
--disconnect con1

--connection default

drop user 'a123456789-123456789-123456789-123456789-123456789-123456789-123456789-123456789'@'localhost';

alter table mysql.user modify User char(16) binary not null default '';
alter table mysql.db modify User char(16) binary not null default '';
alter table mysql.tables_priv modify User char(16) binary not null default '';
alter table mysql.columns_priv modify User char(16) binary not null default '';
alter table mysql.procs_priv modify User char(16) binary not null default '';
alter table mysql.proc modify definer char(77) collate utf8_bin not null default '';
alter table mysql.event modify definer char(77) collate utf8_bin not null default '';
flush privileges;