Error with "return query" ( "return next" working ) with custom type

[Rémi Cura <remi.cura@xxxxxxxxx>]

Hey dear lists,

Here is a self contained example showing strange behavior from a real life example concerning the use of postgis_topology topogeometry type.

The problem is :

when trying to return setof topogeometry,

the "return query"  gives an error of type where there is none, and the return next is working fine.

The precise error message is ERROR 42804

"ERROR:  structure of query does not match function result type

DETAIL:  Returned type ttt.fake_topogeometry does not match expected type integer in column 1.

CONTEXT:  PL/pgSQL function ttt.testtopogeom(ttt.fake_topogeometry) line 9 at RETURN QUERY

"

Is it ok, postres bug, postgis bug?

What are the possible corrections?

Here is the self contained code stored in the "ttt" schema.

DROP SCHEMA IF EXISTS ttt CASCADE;

CREATE SCHEMA ttt;

DROP TYPE IF EXISTS ttt.fake_topogeometry CASCADE;

CREATE TYPE ttt.fake_topogeometry AS

   (topology_id integer,

    layer_id integer,

    id integer,

    a_type integer);

DROP FUNCTION IF EXISTS ttt.testTopogeom(test_topom ttt.fake_topogeometry);

CREATE FUNCTION ttt.testTopogeom(test_topom ttt.fake_topogeometry)

RETURNS SETOF ttt.fake_topogeometry AS

$BODY$

-- this function is an empty function to test return of multiple topogeom

DECLARE

the_topo ttt.fake_topogeometry;

BEGIN

RETURN NEXT (1,1,1,1)::ttt.fake_topogeometry;

--RETURN NEXT (3,3,3,3)::ttt.fake_topogeometry;

RETURN QUERY  SELECT (1,1,1,1)::ttt.fake_topogeometry as foo;

-- UNION 

--SELECT  (3,3,3,3)::ttt.fake_topogeometry as foo

RETURN  ;

END ;

$BODY$

LANGUAGE plpgsql IMMUTABLE;

SELECT *

FROM ttt.testTopogeom((2,2,2,2)::ttt.fake_topogeometry);