--diff-filter could use option for pre-rename files

I've been trying to hook together a build script and a GIT repo.

At one points it makes the following calls:

git diff --find-copies-harder --find-renames=101% --name-only 
--diff-filter=ACMRT 'refs/tags/0.0.25' 'refs/tags/0.0.27' > modified.txt
git diff --find-copies-harder --find-renames=101% --name-only 
--diff-filter=D 'refs/tags/0.0.25' 'refs/tags/0.0.27' > deleted.txt

If a file was renamed, but otherwise unchanged (and needs to be deleted 
by the build script), the files' original name does not appear on either 
list. Or, as far as I can tell, at all.

My current scripted workaround is something like

older = `git ls-tree --name-only --full-tree -r 'refs/tags/0.0.25'`
newer = `git ls-tree --name-only --full-tree -r 'refs/tags/0.0.27'`
deleted = older - newer
(puts deleted in deleted.txt)

Ideally this would just be a diff-filter option, say, --diff-filter=DE

-Nathan Bush