anchor.diff:  (defmethod* (setf window-viewport-position) (x y (pane clim-stream-pane))
     (scroll-extent pane x y))
   
  -#+NIL
   (defun scroll-area (pane dx dy)
     (let ((transform (sheet-transformation pane)))
       ;; Region has been "scrolled" already.
       (with-bounding-rectangle* (x1 y1 x2 y2) (sheet-region pane)
  -      (multiple-value-bind (destx desty)
  -	  (transform-position transform x1 y1)
  -	(multiple-value-bind (srcx srcy)
  -	    (transform-position transform (- x1 dx) (- y1 dy))
  -	  (format *debug-io* "dx ~S dy ~S srcx ~S srcy ~S destx ~S desty ~S~%"
  -		  dx dy srcx srcy destx desty)
  +      (multiple-value-bind (srcx srcy)
  +	  (untransform-position transform 0 0)
  +	(multiple-value-bind (destx desty)
  +	    (untransform-position transform dx dy)
   	  (copy-area pane  srcx srcy (- x2 x1) (- y2 y1) destx desty))))))
   
  -#+NIL
   (defmethod scroll-extent ((pane clim-stream-pane) x y)
     (when (is-in-scroller-pane pane)
       (let ((new-x (max x 0))
  
positive.code: ;;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  ;;; Boston, MA  02111-1307  USA.
  
  ;;; $Id: panes.lisp,v 1.79 2002-05-05 03:41:03 adejneka Exp $
  
  (in-package :CLIM-INTERNALS)
  
  
negative.code: 		dy (- y0 new-y))
  	  ;; alter the sheet transformation to reflect the new position
  	  (setf (sheet-transformation pane)
  	    (make-translation-transformation (- x) (- y)))
            (update-scroll-bars pane entire-region new-x new-y)
  	  (with-bounding-rectangle* (x1 y1 x2 y2) (sheet-region pane)
  	    (cond
  	     ((and (zerop dx)
  		   (< (abs dy) (- y2 y1)))
  	      (scroll-area pane 0 dy)
  	      (cond
  	       ((< dy 0)
  		(medium-clear-area (sheet-medium pane) 0 (+ y2 dy) (- x2 x1) (- y2 y1))
  		(stream-replay pane (make-bounding-rectangle x1 (+ y2 dy) x2 y2)))
  	       (t
  		(medium-clear-area (sheet-medium pane) 0 0 (- x2 x1) dy)
  		(stream-replay pane (make-bounding-rectangle x1 y1 x2 (+ y1 dy))))))
  	     ((and (zerop dy)
  		   (< (abs dx) (- x2 x1)))
  	      (scroll-area pane dx 0)
  	      (cond
  	       ((< dx 0)
  		(medium-clear-area (sheet-medium pane) (+ x2 dx) 0 (- x2 x1) (- y2 y1))
  		(stream-replay pane (make-bounding-rectangle (+ x2 dx) y1 x2 y2)))
  	       (t
  		(medium-clear-area (sheet-medium pane) 0 0 dx (- y2 y1))
  		(stream-replay pane (make-bounding-rectangle x1 y1 (+ x1 dx) y2)))))
  	     (t
  	      (medium-clear-area (sheet-medium pane) 0 0 (- x2 x1) (- y2 y1))
  	      (stream-replay pane (sheet-region pane))))))))))
  
  (defmethod stream-set-input-focus ((stream clim-stream-pane))
  