anchor.diff:  (defparameter *scrollbar-thickness* 17)
   
   (defclass scroller-pane (composite-pane)
  -  ((scroll-bar :type (member t :vertical :horizontal)
  -	       :initform t
  -	       :initarg :scroll-bar
  -	       :accessor scroller-pane-scroll-bar)
  +  ((scroll-bar :type (member t :vertical :horizontal nil)
  +               ;; ### Note: I added NIL here, so that the application
  +               ;; programmer can switch off scroll bars alltogether. 
  +               ;; The spec though has it neither in the description of
  +               ;; SCROLLER-PANE, nor in the description of
  +               ;; MAKE-CLIM-STREAM-PANE, but in OPEN-WINDOW-STREAM.
  +               ;;
  +               ;; One might argue that in case of no scroll-bars the
  +               ;; application programmer can just skip the scroller
  +               ;; pane altogether. But I think that the then needed
  +               ;; special casing on having a scroller pane or a bare
  +               ;; viewport at hand is an extra burden, that can be
  +               ;; avoided.
  +               ;; --GB 2005-11-29
  +               :initform t
  +               :initarg :scroll-bar
  +               :accessor scroller-pane-scroll-bar)
      (viewport   :initform nil)
      (vscrollbar :initform nil)
      (hscrollbar :initform nil)
  
positive.code: ;;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  ;;; Boston, MA  02111-1307  USA.
  
  ;;; $Id: panes.lisp,v 1.160 2005-11-28 15:24:37 gbaumann Exp $
  
  (in-package :clim-internals)
  
  
negative.code:                        :min-value 0
                         :max-value 1))
        (sheet-adopt-child pane vscrollbar))
      (when (member scroll-bar '(:horizontal t))
        (setq hscrollbar
              (make-pane 'scroll-bar-pane
                         :orientation :horizontal
  