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@yahoo.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;
                                                   ^