BUG #7715: hstore "exists" should use same index as "?" operator

The following bug has been logged on the website:

Bug reference: 7715
Logged by: Ian Dees
Email address: ian(dot)dees(at)gmail(dot)com
PostgreSQL version: 9.1.6
Operating system: Ubuntu 11.04
Description:

Currently the hstore documentation [0] says "hstore has GiST and GIN index
support for the @>, ?, ?& and ?| operators", but the "?" character is a
special character in JDBC and JDBC always tries to replace it with a
parameter [1]. Because of the intermingling of these two issues, it's
impossible to use the index when querying an hstore row using JDBC with the
"?" operator.

[0] http://www.postgresql.org/docs/9.1/static/hstore.html
[1]
http://stackoverflow.com/questions/11940401/escaping-hstore-contains-operators-in-a-jdbc-prepared-statement