Fail to execute query in tidb but succeeded in MySQL

[Nickelth]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

CREATE TABLE `t43` (`a` char(5) CHARACTER SET latin1);

INSERT INTO `t43` VALUES (x'f6');

SELECT t43.a FROM  t43 WHERE (('uWHghV')REGEXP(t43.a));

2. What did you expect to see? (Required)

Query executed successfully.

3. What did you see instead (Required)

mysql> SELECT t43.a FROM  t43 WHERE (('uWHghV')REGEXP(t43.a));
ERROR 1105 (HY000): invalid input value: FromUtf8Error { bytes: [246], error: Utf8Error { valid_up_to: 0, error_len: Some(1) } }

4. What is your TiDB version? (Required)

Release Version: v8.4.0-alpha-325-g74034d4ac2
Edition: Community
Git Commit Hash: 74034d4ac243b3c14dbf5f8a9edb92e740da4212
Git Branch: master
UTC Build Time: 2024-10-06 19:04:12
GoVersion: go1.22.5
Race Enabled: false
Check Table Before Drop: false
Store: tikv