BUG #4817: Dump of 8.3 hstore not restorable to 8.4 (RECHECK)

The following bug has been logged online:

Bug reference:      4817
Logged by:          David Blewett
Email address:      david@dawninglight.net
PostgreSQL version: 8.4beta2
Operating system:   Gentoo Linux
Description:        Dump of 8.3 hstore not restorable to 8.4 (RECHECK)
Details:

In testing the beta to see if my planner issues might be resolved, I ran
into a situation where the 8.4 pg_dump created a dump for the hstore contrib
module which would not restore against 8.4.

Here is the problem SQL:
--
-- Name: gin_hstore_ops; Type: OPERATOR CLASS; Schema: public; Owner:
postgres
--

CREATE OPERATOR CLASS gin_hstore_ops
    DEFAULT FOR TYPE hstore USING gin AS
    STORAGE text ,
    OPERATOR 7 @>(hstore,hstore) RECHECK ,
    OPERATOR 9 ?(hstore,text) ,
    FUNCTION 1 bttextcmp(text,text) ,
    FUNCTION 2 gin_extract_hstore(internal,internal) ,
    FUNCTION 3 gin_extract_hstore_query(internal,internal,smallint) ,
    FUNCTION 4 gin_consistent_hstore(internal,smallint,internal);

--
-- Name: gist_hstore_ops; Type: OPERATOR CLASS; Schema: public; Owner:
postgres
--

CREATE OPERATOR CLASS gist_hstore_ops
    DEFAULT FOR TYPE hstore USING gist AS
    STORAGE ghstore ,
    OPERATOR 7 @>(hstore,hstore) RECHECK ,
    OPERATOR 9 ?(hstore,text) RECHECK ,
    OPERATOR 13 @(hstore,hstore) RECHECK ,
    FUNCTION 1 ghstore_consistent(internal,internal,integer) ,
    FUNCTION 2 ghstore_union(internal,internal) ,
    FUNCTION 3 ghstore_compress(internal) ,
    FUNCTION 4 ghstore_decompress(internal) ,
    FUNCTION 5 ghstore_penalty(internal,internal,internal) ,
    FUNCTION 6 ghstore_picksplit(internal,internal) ,
    FUNCTION 7 ghstore_same(internal,internal,internal);

This generates the following errors:
ERROR:  RECHECK is no longer supported at character 131
ERROR:  RECHECK is no longer supported at character 136

I worked around this by installing the 8.4 version of hstore and ignoring
those particular errors. However, why would pg_dump generate syntax that
isn't supported any longer?

David Blewett