Undeterministic result of deterministic query

[DerZc]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

Hi, in the following test case, the SELECT query should return a deterministic result; however, when I run this test case 10 times. 5 of them return an empty result, and 5 of them return 1 row.

CREATE TABLE t0(c0 FLOAT);
CREATE TABLE t1 LIKE t0;
REPLACE INTO t1 VALUES (0.26201291039277286);
INSERT IGNORE  INTO t0(c0) VALUES (0.47821491788303083);
ALTER TABLE t0 MODIFY c0 TEXT;
UPDATE t1 SET c0=(CASE -518779582 WHEN INSERT(((t1.c0)OR(((t1.c0) IS NULL))), true, FORMAT(DEFAULT(t1.c0), t1.c0), t1.c0) THEN '(ymlif\r' ELSE ((t1.c0)>=(t1.c0)) END );
ALTER TABLE t1 MODIFY c0 DECIMAL;
REPLACE INTO t1(c0) VALUES (-1539818217), (1719485563), (-384323401);
INSERT INTO t0 VALUES ('1+[Sic') ON DUPLICATE KEY UPDATE c0=-350963399;
SELECT t0.c0 FROM  t0 NATURAL RIGHT JOIN t1 GROUP BY NULL HAVING t0.c0;

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

The SELECT query should always return the same result.

3. What did you see instead (Required)

The SELECT query returns different results.

4. What is your TiDB version? (Required)

Release Version: v9.0.0-beta.2.pre-551-g71caddf56d\nEdition: Community\nGit Commit Hash: 71caddf\nGit Branch: master\nUTC Build Time: 2025-10-11 06:46:47\nGoVersion: go1.23.12\nRace Enabled: false\nCheck Table Before Drop: false\nStore: unistore\nKernel Type: Classic