The following bug has been logged on the website:
Bug reference: 19046
Logged by: Runyuan He
Email address: runyuan@berkeley.edu
PostgreSQL version: 18rc1
Operating system: Linux (x86)
Description:
Bug Description:
When using json_array() function with a column reference from table t inside
a subquery, and then performing a RIGHT JOIN with condition FALSE, the
result incorrectly returns [3, 2] instead of the expected NULL value.
Reproducible Example:
CREATE TABLE t(c INT);
INSERT INTO t VALUES (1);
SELECT sub.c FROM
(SELECT json_array(3, 2, t.c) AS c FROM t) AS sub
RIGHT JOIN t ON FALSE;
-- PostgreSQL 16.x: Returns NULL (CORRECT)
-- PostgreSQL 17.6, 17.rc1: Returns [3, 2] (INCORRECT)
-- PostgreSQL 18rc1: Returns [3, 2] (INCORRECT)
SELECT sub.c FROM
(SELECT json_array(3, 2, t.c) AS c FROM t) AS sub;
-- Returns [3, 2, 1] (CORRECT)
SELECT sub.c FROM
(SELECT json_array(3, 2, 1) AS c FROM t) AS sub
RIGHT JOIN t ON FALSE;
-- Returns Null (CORRECT)
