anchor.diff:      (setf (box-layout-mixin-clients sheet)
             (append (box-layout-mixin-clients sheet)
                     (list (make-instance 'box-client
  -                                       :pane child))))))
  +                                       :pane child))))
  +    (when (and (sheet-enabled-p sheet)
  +               (sheet-parent sheet))
  +      (change-space-requirements sheet))))
   
   (defmethod sheet-disown-child :after ((sheet box-layout-mixin) (child sheet) &key errorp)
     (declare (ignore errorp))
     (setf (box-layout-mixin-clients sheet)
           (remove-if (lambda (client)
                        (eq (box-client-pane client) child))
  -                   (box-layout-mixin-clients sheet))))
  +                   (box-layout-mixin-clients sheet)))
  +  (when (and (sheet-enabled-p sheet)
  +             (sheet-parent sheet))
  +    (change-space-requirements sheet)))
   
   
   (defclass rack-layout-mixin (box-layout-mixin)
  
positive.code: (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)
  
negative.code: ;;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  ;;; Boston, MA  02111-1307  USA.
  
  ;;; $Id: panes.lisp,v 1.121 2003/05/31 21:43:15 gilbert Exp $
  
  (in-package :clim-internals)
  
  