BUG #3116: attribute has wrong type

The following bug has been logged online:

Bug reference:      3116
Logged by:          Greg Sabino Mullane
Email address:      greg@turnstep.com
PostgreSQL version: 8.1.8
Operating system:   Linux
Description:        attribute has wrong type
Details:

Reproduced on 8.2.3, 8.1.8, and CVS HEAD:

CREATE OR REPLACE FUNCTION gregtest(int) RETURNS varchar
LANGUAGE sql AS $$ SELECT 'abc'::text; $$;

-- Works:
SELECT gregtest(123);

-- Does not:
SELECT boom FROM
( SELECT 123, gregtest(123) AS boom) AS tmp;

ERROR:  attribute 2 has wrong type
DETAIL:  TABLE has type text, but query expects character varying.