[viewvc-dev] Is diff to "the previous" revision currently possible?

We would like to use a ViewVC query similar to:
"?r1=PREV&r2=5023"

...for both CVS and SVN repositories...

I see from the ViewVC source code that there is a "prev_rev" python proc in
viewvc.py. Is this a planned feature or should I submit a feature request?
(Or is there a way to do it now and I am simply overlooking it?)



Thanks for any info,
David Cole
Kitware, Inc.