ALTER TABLE .. ADD PRIMARY KEY .. USING INDEX has dump-restore hazard

Consider:

rhaas=# create table foo (a text);
CREATE TABLE
rhaas=# create unique index on foo (a collate "C");
CREATE INDEX
rhaas=# alter table foo add primary key using index foo_a_idx;
ALTER TABLE
rhaas=# \d foo   Table "public.foo"Column | Type | Modifiers
--------+------+-----------a      | text | not null
Indexes:   "foo_a_idx" PRIMARY KEY, btree (a COLLATE "C")

Now dump and restore this database.  Then:

rhaas=# \d foo   Table "public.foo"Column | Type | Modifiers
--------+------+-----------a      | text | not null
Indexes:   "foo_a_idx" PRIMARY KEY, btree (a)

Notice that the collation specifier is gone.  Oops.

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company