Revision 1483186

Merge the r1482969 group from trunk:

 * r1482969, r1482970
   Fix issue #4366 ("client SEGFAULTs diffing a repos rev in which an
   empty file was added").
   Justification:
     SEGFAULTs are consider rude in polite company.
   Votes:
     +1: cmpilato, philip, rhuijben