-- Minimal repro: a json_array() expression index over a composite type.
-- 18 rejects the CREATE INDEX; 19 accepts it, and after ALTER TYPE the
-- index scan and a sequential scan disagree until REINDEX.
CREATE TYPE c AS (x int);
CREATE TABLE t (v c);
INSERT INTO t VALUES (ROW(1));
CREATE INDEX t_i ON t ((json_array(v RETURNING jsonb)));
ALTER TYPE c ADD ATTRIBUTE y int;
SET enable_seqscan = off;
SELECT count(*) AS index_scan FROM t
  WHERE json_array(v RETURNING jsonb) = '[{"x": 1, "y": null}]';
RESET enable_seqscan;
SET enable_indexscan = off;
SET enable_bitmapscan = off;
SELECT count(*) AS seq_scan FROM t
  WHERE json_array(v RETURNING jsonb) = '[{"x": 1, "y": null}]';
RESET ALL;
REINDEX INDEX t_i;
SET enable_seqscan = off;
SELECT count(*) AS index_scan_after_reindex FROM t
  WHERE json_array(v RETURNING jsonb) = '[{"x": 1, "y": null}]';