Followup to r28065: since we switched from using the "result" hash to the "cache" hash, we now have to watch out for explicitly represented negative cache results.
Followup to r28065: since we switched from using the "result" hash to
the "cache" hash, we now have to watch out for explicitly represented
negative cache results.

* subversion/libsvn_fs_util/mergeinfo-sqlite-index.c
  (index_path_mergeinfo): Treat NEGATIVE_CACHE_RESULT the same as
   NULL.

jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion