Merge the r1496127 group from trunk:

 * r1496127, r1567492, r1567494
   Fix occasional failure of checkout_tests.py 12.
   Justification:
     Spurious FAILs confuse people testing the release.
   Votes:
     +1: breser, danielsh, rhuijben
     +1: philip (without r1567492, r1567494)


git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/1.8.x@1567731 13f79535-47bb-0310-9956-ffa450edef68