BUG #2426: perl function that returns setof composite type

The following bug has been logged online:

Bug reference:      2426
Logged by:          Chana Slutzkin
Email address:      chana@cs.huji.ac.il
PostgreSQL version: 8.1.3
Operating system:   FreeBSD 6.1
Description:        perl function that returns setof composite type
Details:

The code below works fine on version 8.0.3.
However, on version 8.1.3, the last query returns
the following error:

set-valued function called in context that cannot accept a set

Hence there does not seem to be an way to use
a perl function that returns 'setof composite'
on non-constant input.

------------------------------------------------------
DROP TABLE num CASCADE;
CREATE TABLE num (n int);
COPY num FROM stdin;
1
2
3
\.

CREATE OR REPLACE FUNCTION sqlget(num) RETURNS SETOF num AS $$
   SELECT $1.n
$$ LANGUAGE SQL;

CREATE OR REPLACE FUNCTION perlget(num) RETURNS SETOF num AS $$
  return [{n=>$_[0]->{n}}];
$$ LANGUAGE plperl;

SELECT (sqlget(num.*)).* FROM num;
SELECT (perlget(num.*)).* FROM num;