I wasn’t aware of this, but apparently DragonFly’s version of patch(1) comes from OpenBSD and NetBSD.  FreeBSD’s old version of patch is being replaced by this and modified to match the old one’s behaviors.  It would be worthwhile to bring these changes back, if possible, just to reduce the differences in a utility that’s already been around the world, so to speak.

As an aside, I always thought patch was one of Larry Wall’s unsung successes, and I’m entertained by any program that has “Hmm…” as one of its official outputs.