Restore the behavior of reporting the src-right version of added nodes to
what we did with the old diff engine: always 0 for adds/copies.

* subversion/libsvn_wc/diff_editor.c
  (svn_wc__diff_local_only_file): Don't overwrite the BASE revision with the
    original revision in diff headers.
  (wrap_file_added): Always pass 0 as right revision.

* subversion/tests/cmdline/diff_tests.py
  (diff_git_format_wc_wc): Restore an asumption changed in r1446339.
  (diff_dir_replaced_by_file): New test, verifying the current behavior.
  (test_list): Add test.

* subversion/tests/cmdline/merge_tests.py
  (merge_in_new_file_and_diff): Expect directory changes after the changes to
    files in the directory as that is the only valid way to drive the new (and
    old) diff. The revision numbers are fixed by the rest of this patch.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1446390 13f79535-47bb-0310-9956-ffa450edef68