Consider the following test case:

CREATE TABLE t0(c0);
INSERT INTO t0 VALUES ('1');
CREATE VIEW v0(c0) AS SELECT CASE WHEN 1 THEN json_patch('1', '1') END FROM t0 GROUP BY t0.c0;
SELECT * FROM v0 WHERE json_quote(v0.c0) != '1';

This query produces an empty result, which I believe, is unexpected. Since json_quote(v0.c0) will return '”1”', which not equals to '1', so this condition is true and I expect the result to be '1'. Note that this reproduces also on the latest trunk version (4fe1419a).