Unexpected Results Using NULLIF #15121

CrateDB version

5.6.0-SNAPSHOT built ff1e7f7

CrateDB setup information

Manual build following the instructions here: https://github.com/crate/crate/blob/master/devs/docs/basics.rst

Problem description

The third SELECT returns an empty result, which is surprising, given that the result of second query is TRUE. The value of the NULLIF expression is TRUE, and thus the third query should return the whole table.

Steps to Reproduce

CREATE TABLE t0(c0 INTEGER);
INSERT INTO t0(c0) VALUES (NULL);

SELECT * FROM t0; -- NULL
SELECT NULLIF(2, c0)!=1 FROM t0; -- TRUE
SELECT * FROM t0 WHERE NULLIF(2, c0)!=1; 

Actual Result

empty table

Expected Result

NULL