* subversion/mod_dav_svn/util.c
  (dav_svn__build_uri): Avoid segfault when root_path is "". This case
    should be unreachable after the other change, but this is hard to tell.

* subversion/mod_dav_svn/version.c
  (get_option):
    Don't advertise http-v2 support urls unless there is an actual repository
    These urls won't work anyway, as that would require a working repository
    at this location.

Found by: lgo


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1557094 13f79535-47bb-0310-9956-ffa450edef68