INSERT fails to return an error after transaction abort

/* init */ CREATE TABLE t(c1 INT PRIMARY KEY, c2 INT UNIQUE);

/* init */ INSERT INTO t(c1) VALUES (8);

/* t1 */ BEGIN;

/* t1 */ UPDATE t SET c1=5, c2=7 WHERE -19;

/* t2 */ BEGIN;

/* t2 */ DELETE FROM t WHERE -15; -- blocked

/* t1 */ UPDATE t SET c1=3 WHERE 0.5;

/* t2 */ DELETE FROM t WHERE -15; -- deadlock

/* t2 */ ERROR 1213 (40001): Deadlock found when trying to get lock; try restarting transaction

/* t1 */ COMMIT;

/* t2 */ INSERT IGNORE INTO t(c1) VALUES (2);

/* t2 */ SELECT * FROM t FOR UPDATE; -- [(2, NULL), (3, 7)]

/* t2 */ ROLLBACK;

/* t2 */ SELECT * FROM t FOR UPDATE; -- [(3, 7)]