BUG #3592: alter function rename to doesn't work

The following bug has been logged online:

Bug reference: 3592
Logged by: Ow
Email address: nikeow(at)yahoo(dot)com
PostgreSQL version: 8.2.4
Operating system: Linux (gentoo)
Description: alter function rename to doesn't work
Details:

=> create or replace function dbo.test(AA text) returns varchar(4) as
-> $$
$> BEGIN
$> return AA;
$> END;
$> $$ language plpgsql;
CREATE FUNCTION

=> select dbo.test('text');
test
------
text
(1 row)

=> alter function dbo.test(text) rename to dbo.test_rename;
ERROR: syntax error at or near "."
LINE 1: alter function dbo.test(text) rename to dbo.test_rename;
^