BUG #1688: inheritance and foreign key creation problem

The following bug has been logged online:

Bug reference: 1688
Logged by:
Email address: wrobell(at)pld-linux(dot)org
PostgreSQL version: 8.0.3
Operating system: Linux
Description: inheritance and foreign key creation problem
Details:

-----------
create table employee (
__key__ integer,
name varchar(10) not null,
surname varchar(20) not null,
phone varchar(12) not null,
unique (name, surname),
primary key (__key__)
);

create table boss (
dep_fkey integer unique
) inherits(employee);

create table department (
__key__ integer,
boss_fkey integer unique,
primary key (__key__),
foreign key (boss_fkey) references boss(__key__) initially deferred
);

-----------

We can see that boss relation has __key__ column (inherited from employee
relation), but when executing above script PostgreSQL fails with message:

psql:script.sql:20: ERROR: there is no unique constraint matching given
keys for referenced table "boss"