BUG #18188: wrong varnullingrels

The following bug has been logged on the website:

Bug reference: 18188
Logged by: Gábor Szabó
Email address: fotonszekta(at)gmail(dot)com
PostgreSQL version: 16.1
Operating system: windows, ubuntu
Description:

/*
wrong varnullingrels:
Needed a table function call, a LEFT JOIN with that table, and an other join
AFTER the left join.
(The first join must be LEFT, the second join can be any tpye. No data in
tables needed.)

Reproduced on:
Windows 11 + PostgreSQL 16.0, 16.1
Ubuntu 22.04.3 + PostgreSQL 16.1

Tested with no error:
Windows 11 + PostgrSQL 15.4, 15.5,
Ubuntu 22.04.3 + PostgreSQL 12.17, 12.16,
Ubuntu 20.04.6 + PostgreSQL 14.9

Error message from verbose log:

ERROR: XX000: wrong varnullingrels (b) (expected (b 3)) for Var 2/1
LOCATION: search_indexed_tlist_for_var, setrefs.c:2807
STATEMENT: SELECT

table_2.disp,

table_3.table_3_id

FROM table_1

LEFT JOIN table_2 ON table_2.table_2_id = table_1.table_2_id

LEFT JOIN table_3 ON table_3.table_3_id = table_1.table_3_id

script to reproduce:
*/
--
-- PostgreSQL database dump
--

-- Dumped from database version 16.1
-- Dumped by pg_dump version 16.1

SET statement_timeout = 0;
SET lock_timeout = 0;
SET idle_in_transaction_session_timeout = 0;
SET client_encoding = 'UTF8';
SET standard_conforming_strings = on;
SELECT pg_catalog.set_config('search_path', '', false);
SET check_function_bodies = false;
SET xmloption = content;
SET client_min_messages = warning;
SET row_security = off;

--
-- Name: public; Type: SCHEMA; Schema: -; Owner: postgres
--

-- *not* creating schema, since initdb creates it

ALTER SCHEMA public OWNER TO postgres;

SET default_tablespace = '';

SET default_table_access_method = heap;

--
-- Name: table_2; Type: TABLE; Schema: public; Owner: postgres
--

CREATE TABLE public.table_2 (
table_2_id integer NOT NULL
);

ALTER TABLE public.table_2 OWNER TO postgres;

--
-- Name: disp(public.table_2); Type: FUNCTION; Schema: public; Owner:
postgres
--

CREATE FUNCTION public.disp(p_table_2 public.table_2) RETURNS integer
LANGUAGE sql
AS $$

SELECT p_table_2.table_2_id

$$;

ALTER FUNCTION public.disp(p_table_2 public.table_2) OWNER TO postgres;

--
-- Name: table_1; Type: TABLE; Schema: public; Owner: postgres
--

CREATE TABLE public.table_1 (
table_1_id integer NOT NULL,
table_2_id integer,
table_3_id integer
);

ALTER TABLE public.table_1 OWNER TO postgres;

--
-- Name: table_3; Type: TABLE; Schema: public; Owner: postgres
--

CREATE TABLE public.table_3 (
table_3_id integer NOT NULL
);

ALTER TABLE public.table_3 OWNER TO postgres;

--
-- Data for Name: table_1; Type: TABLE DATA; Schema: public; Owner:
postgres
--

COPY public.table_1 (table_1_id, table_2_id, table_3_id) FROM stdin;
\.

--
-- Data for Name: table_2; Type: TABLE DATA; Schema: public; Owner:
postgres
--

COPY public.table_2 (table_2_id) FROM stdin;
\.

--
-- Data for Name: table_3; Type: TABLE DATA; Schema: public; Owner:
postgres
--

COPY public.table_3 (table_3_id) FROM stdin;
\.

--
-- Name: table_1 table_1_pkey; Type: CONSTRAINT; Schema: public; Owner:
postgres
--

ALTER TABLE ONLY public.table_1
ADD CONSTRAINT table_1_pkey PRIMARY KEY (table_1_id);

--
-- Name: table_2 table_2_pkey; Type: CONSTRAINT; Schema: public; Owner:
postgres
--

ALTER TABLE ONLY public.table_2
ADD CONSTRAINT table_2_pkey PRIMARY KEY (table_2_id);

--
-- Name: table_3 table_3_pkey; Type: CONSTRAINT; Schema: public; Owner:
postgres
--

ALTER TABLE ONLY public.table_3
ADD CONSTRAINT table_3_pkey PRIMARY KEY (table_3_id);

--
-- Name: SCHEMA public; Type: ACL; Schema: -; Owner: postgres
--

REVOKE USAGE ON SCHEMA public FROM PUBLIC;
GRANT ALL ON SCHEMA public TO PUBLIC;

--
-- PostgreSQL database dump complete
--

-- restore search_path:
SELECT pg_catalog.set_config('search_path', 'pg_catalog, public', false);

-- query:
SELECT
table_2.disp,
table_3.table_3_id
FROM table_1
LEFT JOIN table_2 ON table_2.table_2_id = table_1.table_2_id
LEFT JOIN table_3 ON table_3.table_3_id = table_1.table_3_id;