Unexpected error "Cannot convert NULL value to non-Nullable type"

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

DROP TABLE IF EXISTS tb0;
CREATE TABLE tb0 (c0 VARCHAR(70) NOT NULL);
ALTER TABLE tb0 SET TIFLASH REPLICA 1;

SELECT /*+ read_from_storage(tiflash[t0]) */ t0.c0 AS col_0 FROM tb0 AS t0 WHERE ((ACOS(2) NOT IN (SELECT 1)));

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

no error

3. What did you see instead (Required)

[HY000][1105] other error for mpp stream: Code: 349, e.displayText() = DB::Exception: Cannot convert NULL value to non-Nullable type, e.what() = DB::Exception,

4. What is your TiFlash version? (Required)

+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| tidb_version()                                                                                                                                                                                                                                                                                |
+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Release Version: v9.0.0-beta.2.pre-250-ga6d415f24a
Edition: Community
Git Commit Hash: a6d415f24a7d182ebca3d189c457d9044537028f
Git Branch: HEAD
UTC Build Time: 2025-08-03 10:01:12
GoVersion: go1.23.11
Race Enabled: false
Check Table Before Drop: false
Store: tikv
Kernel Type: Classic |
+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+

Start by running the supplied SQL reproduction against TiFlash, including the ACOS predicate, subquery, and read_from_storage hint. Trace the resulting NULL-to-non-Nullable error through the affected query execution path; done means the query completes without the reported error and regression coverage verifies the case.