--error 0,ER_CANNOT_USER
DROP USER otto@'localhost';
CREATE USER otto@'localhost';

GRANT PROCESS ON *.* TO otto@'localhost';
GRANT PROCESS ON *.* TO ''@'localhost';

--echo ---- Establish connection otto (user=otto) ----
connect (otto,localhost,otto,,test);

--echo ---- Establish connection anonymous (user=''=<anonymous>) ----
connect (anonymous,localhost,'',,test);
SHOW GRANTS;
SHOW processlist;
SELECT * FROM information_schema.processlist;

--echo ---- Switch to connection otto ----
SHOW GRANTS;
SHOW processlist;
SELECT * FROM information_schema.processlist;

--echo ---- Switch to connection default ----
connection default;
REVOKE PROCESS ON *.* FROM otto@'localhost';
REVOKE PROCESS ON *.* FROM ''@'localhost';

--echo ---- Close connections otto + anonymous and establish them again ----
disconnect otto;
disconnect anonymous;

--echo ---- Establish connection otto (user=otto) ----
connect (otto,localhost,otto,,test);
--disable_abort_on_error
SHOW GRANTS;
SHOW processlist;
SELECT * FROM information_schema.processlist;
--enable_abort_on_error

--echo ---- Establish connection anonymous (user=''=<anonymous>) ----
connect (anonymous,localhost,'',,test);
--disable_abort_on_error
SHOW GRANTS;
SHOW processlist;
SELECT * FROM information_schema.processlist;
--enable_abort_on_error

--echo ---- Switch to connection default + close other connections ----
connection default;
DROP USER otto@'localhost';
disconnect otto;
disconnect anonymous;