That would require you to know ahead of time what you're patching, and to have a copy of it on the source machine so you could generate the patch. This would b

That would require you to know ahead of time what you're patching, and to have a copy of it on the source machine so you could generate the patch. This would be automatic. If there's similarity on the target, use it, but without requiring the user to tell you where to find it.