(defun vc-darcs-checkin (files rev comment)

(defun vc-darcs-checkin (files comment)

  (when (not (null rev))
    (error "Cannot specify check-in revision with darcs."))

(defun vc-darcs-checkout (file &optional _editable rev)
  "Check out FILE from the Darcs repository.
EDITABLE is ignored."

(defun vc-darcs-checkout (file &optional rev)
  "Check out FILE from the Darcs repository."

(defun vc-darcs-print-log (files &optional buffer _shortlog start-revision limit)

(defun vc-darcs-print-log (files buffer &optional _shortlog start-revision limit)

(defun vc-darcs-diff (file &optional rev1 rev2 buffer dummy)

(defun vc-darcs-diff (file &optional rev1 rev2 buffer async)