Fix an obscure buglet in libsvn_ra_serf masked by our typical usage of svn_ra_get_mergeinfo().
Fix an obscure buglet in libsvn_ra_serf masked by our typical usage of
svn_ra_get_mergeinfo().

* subversion/libsvn_ra_serf/mergeinfo.c
  (end_element): Don't require that the mergeinfo REPORT response's
    path have any length to it.  As those paths are relative to the
    URL at which the REPORT was aimed, it's quite alright for them to
    be the empty string.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@880461 13f79535-47bb-0310-9956-ffa450edef68

YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,wbond/subversion,YueLinHo/Subversion,wbond/subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,wbond/subversion