SELECT returns an incorrect result

[sayJason]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

Run the following statements.

CREATE TABLE t1 (c1 BOOL NOT NULL);
INSERT INTO t1 VALUES (-127);

SELECT c1 FROM t1 WHERE CAST(IFNULL(t1.c1, '-') AS CHAR); -- actual: {}, expected: {-127}

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

The SELECT statement should return column c1 value

3. What did you see instead (Required)

Nothing is returned by the SELECT statement.

4. What is your TiDB version? (Required)

Release Version: v6.6.0
Edition: Community
Git Commit Hash: f4ca0821fb96a2bdd37d2fb97eb26c07fc58d4e4
Git Branch: heads/refs/tags/v6.6.0
UTC Build Time: 2023-02-17 14:49:02
GoVersion: go1.19.5
Race Enabled: false
TiKV Min Version: 6.2.0-alpha
Check Table Before Drop: false
Store: tikv