Indexed INT comparison returns wrong rows for fractional literal/string, but not DECIMAL cast

Summary

On MariaDB 12.3.1-MariaDB-asan-log (rev 21a0714a), indexed integer comparison still returns wrong rows for fractional literals and strings:

WHERE i = 0.6

WHERE i = '0.6'

Both predicates incorrectly use the index and match rows where i = 1. However, semantically equivalent DECIMAL / folded forms return the correct empty result:

WHERE i = CAST('0.6' AS DECIMAL(10,2))

WHERE i = 0.6 + 0

This appears related to MDEV-38199, but the additional issue here is inconsistent behavior across equivalent constant-coercion paths.

Minimal Reproducer

CREATE TABLE t1 (i INT, KEY (i));

INSERT INTO t1 VALUES (1), (1), (1);

SELECT COUNT(*) FROM t1 WHERE i = 0.6;

-- 3, wrong

SELECT COUNT(*) FROM t1 WHERE i = '0.6';

-- 3, wrong

SELECT COUNT(*) FROM t1 WHERE i = CAST('0.6' AS DECIMAL(10,2));

-- 0, correct

SELECT COUNT(*) FROM t1 WHERE i = 0.6 + 0;

-- 0, correct

SELECT COUNT(*) FROM t1 IGNORE INDEX (i) WHERE i = 0.6;

-- 0, correct

Expected

All predicates should return 0 rows. A fractional value 0.6 should not match integer value 1.

Actual

The indexed literal/string paths return all 3 rows, while DECIMAL cast, folded expression, and IGNORE INDEX return 0 rows.

Environment