BUG #12765: Postgresql ROLE dropped, but its not dropped from pg_roles

The following bug has been logged on the website:

Bug reference: 12765
Logged by: vivek singh
Email address: vivek(dot)singh(at)rackspace(dot)com
PostgreSQL version: 9.3.5
Operating system: CentOS release 6.5
Description:

Postgresql ROLE dropped, but its not dropped from pg_roles view. rolconfig
column of pg_roles still shows the dropped role for associated user.

Bug reproduction:
=================================
postgres=# CREATE ROLE role1;
CREATE ROLE
postgres=# CREATE USER user1;
CREATE ROLE
postgres=# ALTER ROLE user1 SET ROLE TO role1;
ALTER ROLE
postgres=# \du+
List of roles
Role name | Attributes | Member of |
Description
-----------+------------------------------------------------+-----------+-------------
postgres | Superuser, Create role, Create DB, Replication | {} |
role1 | Cannot login | {} |
user1 | | {} |

postgres=# \x
Expanded display is on.
postgres=# SELECT * FROM pg_roles WHERE rolname ='user1';
-[ RECORD 1 ]--+-------------
rolname | user1
rolsuper | f
rolinherit | t
rolcreaterole | f
rolcreatedb | f
rolcatupdate | f
rolcanlogin | t
rolreplication | f
rolconnlimit | -1
rolpassword | ********
rolvaliduntil |
rolconfig | {role=role1}
oid | 24861

postgres=# DROP ROLE role1 ;
DROP ROLE
postgres=# \x
Expanded display is off.
postgres=# \du+
List of roles
Role name | Attributes | Member of |
Description
-----------+------------------------------------------------+-----------+-------------
postgres | Superuser, Create role, Create DB, Replication | {} |
user1 | | {} |

postgres=# \x
Expanded display is on.
postgres=# SELECT * FROM pg_roles WHERE rolname ='user1';
-[ RECORD 1 ]--+-------------
rolname | user1
rolsuper | f
rolinherit | t
rolcreaterole | f
rolcreatedb | f
rolcatupdate | f
rolcanlogin | t
rolreplication | f
rolconnlimit | -1
rolpassword | ********
rolvaliduntil |
rolconfig | {role=role1}
oid | 24861

postgres=# SELECT version();
-[ RECORD 1
]---------------------------------------------------------------------------------------------------------
version | PostgreSQL 9.3.5 on x86_64-unknown-linux-gnu, compiled by gcc
(GCC) 4.4.7 20120313 (Red Hat 4.4.7-4), 64-bit

postgres=#