Keep dir-delta from producing no-op apply_textdelta()s when ignoring ancestry.  This makes many things work better in the case of two mutually merged branches, since editors now know the source and target stream are the same without having to construct the fulltext from the noop txdelta.  As a result, 'svn diff' between the two branches will no longer show a lot of empty diffs.
Keep dir-delta from producing no-op apply_textdelta()s when ignoring
ancestry.  This makes many things work better in the case of two
mutually merged branches, since editors now know the source and target
stream are the same without having to construct the fulltext from the
noop txdelta.  As a result, 'svn diff' between the two branches will
no longer show a lot of empty diffs.

Patch by: Chia-liang Kao <clkao@clkao.org>
(Tweaked by me.)

* subversion/libsvn_repos/delta.c
  (compare_files): New.
  (delta_files): Use the new compare_files() instead of
    svn_fs_contents_changed() when ignore_ancestry is on.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@847926 13f79535-47bb-0310-9956-ffa450edef68

wbond/subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion