Another nasty pg_dump bug in 7.3 (and 7.4?)

This table:

australia=# \d users_users
Table "public.users_users"
Column | Type |
Modifiers
----------------+--------------------------+--------------------------------
---------------------------------
userid | integer | not null default
nextval('public.users_users_userid_seq'::text)
sex | character(1) | not null
suspended | boolean | not null default 'f'
recurring | boolean | not null default 'f'
referrer | integer |
<snip fields>
Check constraints: "$2" (NOT (recurring AND suspended))
"users_users_sex" ((sex = 'M'::bpchar) OR (sex =
'F'::bpchar))
Foreign Key constraints: $1 FOREIGN KEY (referrer) REFERENCES
users_users(userid) ON UPDATE NO ACTION ON DELETE SET NULL

Is dumped like this:

CREATE TABLE users_users (
userid SERIAL,
sex character(1) NOT NULL,
suspended boolean DEFAULT 'f' NOT NULL,
recurring boolean DEFAULT 'f' NOT NULL,
referrer integer,
CHECK ((NOT (recurring AND suspended))),
CONSTRAINT users_users_sex CHECK (((sex = 'M'::bpchar) OR (sex =
'F'::bpchar)))
);
ALTER TABLE ONLY users_users
ADD CONSTRAINT "$1" FOREIGN KEY (referrer) REFERENCES
users_users(userid) ON UPDATE NO ACTION ON DELETE SET NULL;

Restoring this fails with:

ERROR: constraint "$1" already exists for relation "users_users"

Solution:

We need to dump constraint name always for CHECK, or suppress default names
in ADD FOREIGN KEY.

Chris