Incompatible error with MySQL

[sayJason]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

CREATE TABLE t1 (c1 TINYINT);
INSERT INTO t1 VALUES (-128);
SELECT c1 FROM t1 WHERE CAST(POW(c1, c1) AS DECIMAL);
-- ERROR 1105 (HY000): [components/tidb_query_datatype/src/codec/mysql/decimal.rs:1886]: parsing 0.0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000018928834978668395 will truncated

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

SELECT returns empty.

3. What did you see instead (Required)

SELECT returns an error.

4. What is your TiDB version? (Required)

Release Version: v7.0.0
Edition: Community
Git Commit Hash: 7376954
Git Branch: heads/refs/tags/v7.0.0
UTC Build Time: 2023-03-29 13:32:13
GoVersion: go1.20.2
Race Enabled: false
TiKV Min Version: 6.2.0-alpha
Check Table Before Drop: false
Store: tikv