darcs repository web UI and hosting app. This is the main darcsden trunk, which also runs hub.darcs.net. (https://hub.darcs.net)
#105adding a single empty line shows up as an empty diff
A single added empty line shows up as minus nothing plus nothing in the patch view.
Probably just a display issue. For an example, see http://hub.darcs.net/elaforge/karya/patch/20140519003551-2aa8e at fltk/WrappedInput.h :: line 13