Bug #119491 Incorrect results for make_set operation against longtext column
Submitted: 2 Dec 2025 8:21 Modified: 8 Dec 2025 21:10
Reporter: John Jove Email Updates:
Status: Verified Impact on me:
None 
Category:MySQL Server: Optimizer Severity:S1 (Critical)
Version:8.4.7 OS:Any
Assigned to: CPU Architecture:Any

[2 Dec 2025 8:21] John Jove 
Description:
I run the following case, which is expected to return the full content of c1, instead of a truncated value.

How to repeat:
DROP TABLE t1;
CREATE TABLE t1 (c1 LONGTEXT);
INSERT INTO t1 VALUES ('hEGqztW6lIRzG');
SELECT (MIN((MAKE_SET((CAST(1 AS CHAR)), c1, NULL, (IF((ABS(-1)), 1, 0)))))) FROM t1 GROUP BY c1; -- acutal: {hEG}, expected: {hEGqztW6lIRzG}
[8 Dec 2025 21:10] Roy Lyseng 
Verified as described.