Revision 1813794

Start fixing issue #4700: Null updates break last-changed-revision.

Patch by: stsp
          me

* subversion/libsvn_repos/reporter.c
  (update_entry): Use an API that considers not only the two endpoints
    but also the intervening history.

* subversion/tests/cmdline/basic_tests.py
  (null_update_last_changed_revision): Expect to pass.