Parsing the result of a function to a view in an INSERT statement.

I have observed that using a function to provide a default value on a colum=
n of a view or attempting to parse the result of a function to a view in an=
 insert or update statement produces undesirable results.

For example if I have a column named "id" where ever I have made reference =
to NEW.id in the INSERT or UPDATE rules of the view it appears to be replac=
ed with the function call rather than the result of the function call. See =
the example code and output below.

I don't know whether this is the default behaviour and one is expected to p=
rogram around this behaviour or whether this is in fact undesirable behavio=
ur and therefore should be considered as a bug?

Regards
Donald Fraser.

Example SQL Code:

CREATE OR REPLACE FUNCTION public.notice_id(text, int4) RETURNS void AS '=
=20
DECLARE=20
    smsge ALIAS FOR $1;
    id ALIAS FOR $2;
BEGIN=20
    RAISE NOTICE ''%, id is: %'', smsge, id;
    RETURN VOID;
END;' LANGUAGE 'plpgsql' STABLE SECURITY DEFINER;

CREATE TABLE tbl_test1 ( id int4 NOT NULL, id_test2 int4, CONSTRAINT tbl_te=
st1_pkey PRIMARY KEY (id) ) WITHOUT OIDS;
CREATE OR REPLACE RULE rul_tbl_test1_i01 AS ON INSERT TO tbl_test1 DO (SELE=
CT notice_id('id during insert', NEW.id));
CREATE SEQUENCE tbl_test_id_seq INCREMENT 1 MINVALUE 1 MAXVALUE 4294967295 =
CACHE 1;
GRANT ALL ON tbl_test_id_seq TO PUBLIC;

CREATE OR REPLACE VIEW vu_tbl_test1 AS SELECT id, id_test2 FROM tbl_test1;
GRANT SELECT, INSERT, UPDATE ON TABLE vu_tbl_test1 TO PUBLIC;
ALTER TABLE vu_tbl_test1 ALTER COLUMN id SET DEFAULT nextval('tbl_test_id_s=
eq'::text);
CREATE OR REPLACE RULE rul_vu_tbl_test1_01 AS ON INSERT TO vu_tbl_test1 DO =
(SELECT notice_id('id before insert', NEW.id));
CREATE OR REPLACE RULE rul_vu_tbl_test1_02 AS ON INSERT TO vu_tbl_test1 DO =
INSTEAD (INSERT INTO tbl_test1(id, id_test2) VALUES (NEW.id, NEW.id_test2));
CREATE OR REPLACE RULE rul_vu_tbl_test1_03 AS ON INSERT TO vu_tbl_test1 DO =
(SELECT notice_id('id after insert', NEW.id));

Observed output:
Bugs=3D> INSERT INTO vu_tbl_test1 (id_test2) VALUES('2');
NOTICE:  id before insert, id is: 1
NOTICE:  id during insert, id is: 3
NOTICE:  id after insert, id is: 4

Bugs=3D> INSERT INTO vu_tbl_test1 (id,id_test2) VALUES(nextval('tbl_test_id=
_seq'::text),'2');
NOTICE:  id before insert, id is: 5
NOTICE:  id during insert, id is: 7
NOTICE:  id after insert, id is: 8