The uri = uri operator was marked as HASHES, but no hash function or
hash operator class was defined. Hash joins would therefore fail.
Bug report and original patch by Grégoire HUBERT (@chanmix51).
closes#3
Even though uriIsHostSetA() is exported by the uriparser library, it is
not in a header file, so it's not part of the official interface, and
its use causes compiler warnings. So create a local copy and use that.
closes#2
Peter Eisentraut