Unexpected result when using BIT_OR in RIGHT JOIN

[suyZhong]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

DROP DATABASE IF EXISTS db0;
CREATE DATABASE db0;
USE db0;

CREATE  TABLE  t0(c0 INT);

SELECT * FROM t0 RIGHT  JOIN  (SELECT BIT_OR(1970) FROM t0) AS sub0  ON true; -- NULL 0
SELECT * FROM t0 RIGHT  JOIN  (SELECT BIT_OR(1970) FROM t0) AS sub0  ON true WHERE (CASE 1 WHEN NULL THEN true END );
-- Expected: 0 rows
-- Actual: NULL 0

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

The first query returns one row NULL 0, and CASE 1 WHEN NULL THEN true END should be evaluated to NULL; therefore the second query should return an empty set. However, one row is returned. This is also different from MySQL.

3. What did you see instead (Required)

As mentioned above.

4. What is your TiDB version? (Required)

mysql> SELECT tidb_version();
+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| tidb_version()                                                                                                                                                                                                                                                        |
+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Release Version: v8.5.0-alpha-79-g426ce3e570
Edition: Community
Git Commit Hash: 426ce3e57069afbd8f061d7ae39c79d3f9e2ff5d
Git Branch: HEAD
UTC Build Time: 2024-11-09 05:26:34
GoVersion: go1.23.2
Race Enabled: false
Check Table Before Drop: false
Store: unistore |
+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)

[suyZhong]

/label fuzz/sqlancer