CREATE TABLE bug44032(c CHAR(3) CHARACTER SET UTF8) ROW_FORMAT=REDUNDANT
ENGINE=InnoDB;
INSERT INTO bug44032 VALUES('abc'),(0xEFBCA4EFBCA4EFBCA4);
UPDATE bug44032 SET c='DDD' WHERE c=0xEFBCA4EFBCA4EFBCA4;
UPDATE bug44032 SET c=NULL WHERE c='DDD';
UPDATE bug44032 SET c='DDD' WHERE c IS NULL;
DROP TABLE bug44032;
