Unexpected result when using `IS DISTINCT FROM` in `VIEW`

[suyZhong]

Describe the bug

Consider the following test case. The third query should return an empty result set since the second query shows that the expression should be evaluated to null.

Reproduction steps

DROP TABLE IF EXISTS t1 CASCADE;

CREATE  TABLE  t1(c1 VARCHAR(500));
INSERT INTO t1(c1) VALUES ('a');
CREATE VIEW v0(c0) AS SELECT ('a'||NULL) FROM t1;

SELECT * FROM v0; -- null
SELECT ((v0.c0 IS NOT DISTINCT FROM v0.c0) AND (v0.c0 = v0.c0)) FROM v0; -- null
SELECT * FROM v0 WHERE ((v0.c0 IS NOT DISTINCT FROM v0.c0) AND (v0.c0 = v0.c0));
-- Expected: empty result set
-- Actual: null

Expected behavior

Empty result.

MonetDB release

v11.52.0 (hg id: 0d891eb)

Executables source

Self compiled and installed

Operating System

Ubuntu 22.04

Additional context

No response