Function with defval returns wrong result

Hi All,

Following test returns wrong result ..

Testcase ( on 8.4 cvs head )
=======================

CREATE OR REPLACE FUNCTION f1(retval VARCHAR DEFAULT 'Argument') RETURNS
VARCHAR as
$$
BEGIN
return retval;
END;
$$ LANGUAGE plpgsql;

CREATE OR REPLACE FUNCTION f2(p1 IN int, p2 IN VARCHAR DEFAULT f1())
RETURNS VARCHAR AS
$$
BEGIN
RETURN p2;
END;
$$ LANGUAGE plpgsql;

postgres=# select f2(10);
f2
----

(1 row)

When we run the f2() it should return the output as the defvalue of f1()
function, but its returning null.

Thanks,
Rushabh Lathia
www.EnterpriseDB.com