anchor.diff:  
   (defun compute-dirstack-command-eligibility (frame)
     (let* ((stack *directory-stack*)
  -         (state (if stack t nil)))    
  +         (state (if stack t nil)))
       (setf (command-enabled 'com-drop-directory frame) state
             (command-enabled 'com-pop-directory  frame) state
             (command-enabled 'com-swap-directory frame) state)))
  
positive.code:   (list object))
  
  (define-command (com-display-image :name t :command-table filesystem-commands
                                             :menu t)
      ((image-pathname 'pathname
        :default (user-homedir-pathname) :insert-default t))
    (if (probe-file image-pathname)
  
negative.code: 			       (t (caar arg)))
  	   do (format stream " ~S" key-arg))
        (write-char #\) stream))))
  
  
  (define-presentation-method present (object (type generic-function)
                                       stream (view textual-view)
  