[#MDEV-31730] Cursor protocol returns wrong result for 'SELECT MIN(b)-a' where 'a' and 'b' have TIMESTAMP datatype

[MDEV-31730] Cursor protocol returns wrong result for 'SELECT MIN(b)-a' where 'a' and 'b' have TIMESTAMP datatype Created: 2023-07-18 Updated: 2023-11-28
Status:	Open
Project:	MariaDB Server
Component/s:	None
Affects Version/s:	10.4, 10.5, 10.6, 10.9, 10.10, 11.0, 11.1, 11.2
Fix Version/s:	10.4, 10.5, 10.6, 11.0, 11.1, 11.2

Type:

Bug

Priority:

Major

Reporter:

Lena Startseva

Assignee:

Oleksandr Byelkin

Resolution:

Unresolved

Votes:

Labels:

None

Issue Links:

Relates
relates to	MDEV-31005	Make working cursor-protocol	Stalled

Description

Testcase (run MTR test with --cursor-protocol):

CREATE  TABLE t1 (a TIMESTAMP(4), b TIMESTAMP DEFAULT 0) ENGINE=MyISAM;

INSERT IGNORE INTO t1 (a) VALUES ('2001-01-01'),('2003-01-01');

SELECT MIN(b)-a FROM t1;

SELECT (SELECT MIN(b) FROM t1) - a FROM t1;

DROP TABLE t1;

Expected result:

SELECT MIN(b)-a FROM t1;

MIN(b)-a

-20010101000000.0000

SELECT (SELECT MIN(b) FROM t1) - a FROM t1;

(SELECT MIN(b) FROM t1) - a

-20010101000000.0000

-20030101000000.0000

Actual result:

SELECT MIN(b)-a FROM t1;

MIN(b)-a

0.0000

SELECT (SELECT MIN(b) FROM t1) - a FROM t1;

(SELECT MIN(b) FROM t1) - a

0.0000

0.0000

Generated at Thu Feb 08 10:26:03 UTC 2024 using Jira 8.20.16#820016-sha1:9d11dbea5f4be3d4cc21f03a88dd11d8c8687422.