anchor.diff:  (defmethod active-buffer ((interface remote-interface))
     "Get the active buffer for the active window."
     (match (rpc-window-active interface)
  -    ((guard w w) (active-buffer w))))
  +    ((guard w w) (active-buffer w))
  +    (_ (log:warn "No active window."))))
   
   ;; TODO: Prevent setting the minibuffer as the active buffer.
   @export
  
positive.code: 
  (defmethod did-commit-navigation ((buffer buffer) url)
    (setf (name buffer) url)
    (with-result (title (buffer-get-title))
      (setf (title buffer) title))
    (dolist (mode (modes buffer))
      (did-commit-navigation mode url)))
  
negative.code:                              (buffer buffer))
    "Set current window title to 'Next - TITLE - URL."
    (let ((url (name buffer)))
      (with-result* ((title (buffer-get-title :buffer buffer)))
        (setf title (if (str:emptyp title) "" title))
        (setf url (if (str:emptyp url) "<no url/name>" url))
        (rpc-window-set-title interface window
  