SET NAMES latin1;

CREATE OR REPLACE TABLE t1(a INT) ENGINE=MYISAM;

INSERT INTO t1 VALUES (1);

CREATE OR REPLACE TABLE t2(a VARCHAR(50) CHARACTER SET utf8 COLLATE utf8_general_ci) ENGINE=MYISAM;

INSERT INTO t2 VALUES ('1');

-- These queries returns one row as expected

SELECT * FROM t1 WHERE (SELECT CONCAT(a) FROM t1) = (SELECT CONCAT(a) FROM t2);

SELECT * FROM t1 WHERE (SELECT 1,CONCAT(a) FROM t1) = (SELECT 1,CONCAT(a) FROM t2);

-- This returns TRUE as expected (Unicode Character 'NO-BREAK SPACE' (U+00A0) is on the both sides)

SELECT _latin1 0xA0 = _utf8 0xC2A0;

-- This returns one row as expected

SELECT * FROM t1 WHERE (SELECT CONCAT(a, _latin1 0xA0) FROM t1) = (SELECT CONCAT(a,_utf8 0xC2A0) FROM t2);

-- This returns no rows. One row is expected!

SELECT * FROM t1 WHERE (SELECT 1,CONCAT(a, _latin1 0xA0) FROM t1) = (SELECT 1,CONCAT(a,_utf8 0xC2A0) FROM t2);