BUG #2732: pg_get_serial_sequence error

The following bug has been logged online:

Bug reference: 2732
Logged by: Basil Evseenko
Email address: evseenko@sysoft.ru
PostgreSQL version: 8.2beta2
Operating system: Linux 2.6
Description: pg_get_serial_sequence error
Details:

On 8.1.5:
select pg_catalog.pg_get_serial_sequence('album', 'id');
pg_get_serial_sequence
------------------------------
tables.album_id_seq

On 8.2beta2

select pg_catalog.pg_get_serial_sequence('album', 'id');
pg_get_serial_sequence
----------------------------------------
tables.album_title_lower2_idx

So pg_catalog.pg_get_serial_sequence return garbage: index name vs sequence
name