BUG #7677: listen_address 'localhost' listens not to IPv6 ::1

The following bug has been logged on the website:

Bug reference:      7677
Logged by:          Peter Weber
Email address:      bugs@ttyhoney.com
PostgreSQL version: 9.1.6
Operating system:   GNU/Linux (Fedora 17)
Description:        =


Hello!
I just started to use PostgreSQL here, and followed this guide[see 1]. As I
am currently just playing around I wondered, if I can use IPv6. My network
is not IPv6 capabable, but my machine is. So I used "[::1]" instead if
"localhost" or "127.0.0.1". I doesn't work with "[::1]".

Told me, that PostgreSQL is only listening to IPv4:
$ ss -ln
127.0.0.1:5432                               *:*

So I modified the postgresql.conf:
FROM
#listen_addresses =3D 'localhost' =

TO
listen_addresses =3D '::'

And PostgresSQL starts to listen to IPv6:
$ ss -ln
:::5432                              :::*     =


What I expect:
localhost means 127.0.0.1 if IPv4 is available OR ::1 if IPv6 is available.
This is a logical OR, that means booth at the same time are possible.

Thank you
Peter

[1]http://jdbc.postgresql.org/documentation/91/connect.html