Merge r1485350 from trunk:

 * r1485350
   contrib: fix some argument passing.
   Justification:
     More robust that way.
   Votes:
     +1: danielsh, stsp, breser


git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/1.8.x@1485487 13f79535-47bb-0310-9956-ffa450edef68