anchor.diff:                                 :test #'equals))
         (check-type mode-invocation mode-invocation)
         (enable-modes (list (name mode-invocation)) buffer (arguments mode-invocation)))
  -    (disable-modes (mapcar #'name
  -                           (if (exact-p rule)
  -                               (set-difference
  -                                (rememberable-of (modes buffer))
  -                                (included rule) :test #'equals)
  -                               (excluded rule)))
  -                   buffer)))
  +    (alex:when-let ((modes (mapcar #'name
  +                                   (if (exact-p rule)
  +                                       (set-difference
  +                                        (rememberable-of (modes buffer))
  +                                        (included rule) :test #'equals)
  +                                       (excluded rule)))))
  +      (disable-modes modes buffer))))
   
   (defun can-save-last-active-modes (auto-mode url)
     (or (null (last-active-modes-url auto-mode))
  
positive.code:                     (make-instance
                       'hooks:handler
                       :fn (lambda (request-data)
                             (enable-modes '(auto-mode))
                             (hooks:remove-hook (request-resource-hook buffer)
                                                'auto-mode-reenable)
                             request-data)
                       :name 'auto-mode-reenable))
      (disable-modes (uiop:ensure-list modes-to-disable) buffer)
      (enable-modes (uiop:ensure-list modes-to-enable) buffer)
      (nyxt::reload-buffers (list buffer))))
  
  (-> add-modes-to-auto-mode-rules
  
negative.code:           (last-active-modes-url auto-mode) url)))
  
  (defun reapply-last-active-modes (auto-mode)
    (alex:when-let ((modes (mapcar #'name
                                   (set-difference (mode-invocations (modes (buffer auto-mode)))
                                                   (last-active-modes auto-mode)
                                                   :test #'equals))))
      (disable-modes modes (buffer auto-mode)))
    (alex:when-let ((modes (mapcar #'name
                                   (set-difference (last-active-modes auto-mode)
                                                   (mode-invocations (modes (buffer auto-mode)))
                                                   :test #'equals))))
      (enable-modes modes (buffer auto-mode))))
  
  (-> new-page-request-p (request-data) (values boolean &optional))
  (defun new-page-request-p (request-data)
  