anchor.diff:  
   (defmethod handle-event ((pane drawing-app-pane) (event keyboard-event))
     (case (keyboard-event-key-name event)
  -    ((:|r| :r) (redisplay-frame-pane (pane-frame pane) pane :force-p t))
  +    ((:|r| :r) (let ((frame (pane-frame pane)))
  +                 (window-clear (find-pane-named frame 'description))
  +                 (redisplay-frame-pane (pane-frame pane) pane :force-p t)))
       (:| | (repaint-sheet pane clim:+everywhere+))))
   
   (defun %start-benchmark (this-gadget)
  
positive.code: 
  (defun display-render-output (frame pane)
    (declare (ignore pane))
    (let ((output (get-frame-pane frame 'render-output))
          (item (slot-value frame 'current-selection)))
      (let ((description (get-frame-pane *application-frame* 'description)))
        (when item
          (if (slot-value *application-frame* 'signal-condition-p)
              (with-slots (recording-p) clim:*application-frame*
                (let ((pattern (mcclim-raster-image::with-output-to-image-pattern
                                   (stream :width *width*
                                           :height *height*
                                           :border-width *border-width*
                                           :recording-p recording-p)
                                 (clim:draw-rectangle* stream 0 0 *width* *height*
                                                       :filled t
                                                       :ink clim:+grey90+)
                                 (funcall (drawing-test-display-function item) frame stream))))
                  (draw-pattern* output pattern 0 0)
                  (medium-finish-output (sheet-medium output))))
              (handler-case
                  (with-slots (recording-p) clim:*application-frame*
                    (let ((pattern (mcclim-raster-image::with-output-to-image-pattern
                                       (stream :width *width*
                                               :height *height*
                                               :border-width *border-width*
                                               :recording-p recording-p)
                                     (clim:draw-rectangle* stream 0 0 *width* *height*
                                                           :filled t
                                                           :ink clim:+grey90+)
                                     (funcall (drawing-test-display-function item) frame stream))))
                      (draw-pattern* output pattern 0 0)
                      (medium-finish-output (sheet-medium output))))
                (simple-error (condition)
                  (clim:with-drawing-options (description :ink +red+)
                    (format description "Render:~a~%" condition)))))))))
  
  (defun run-drawing-tests ()
    (run-frame-top-level (make-application-frame
  
negative.code:           (drawing-tests-frame (when (eq (type-of frame) 'drawing-app-frame)
                                   (slot-value frame 'drawing-tests-frame))))
        (unless benchmark
          (with-text-style (description (make-text-style :sans-serif :bold :normal))
            (format description "~&~A / ~A:" (drawing-test-category item) (drawing-test-name item)))
          (with-text-style (description (make-text-style :sans-serif :roman :normal))
            (let ((test-description (drawing-test-description item)))
              (format description "~:[~; ~A~]~%" (and test-description (> (length test-description) 0))
                      test-description))))
        (labels ((draw ()
                   (with-slots (recording-p) (or drawing-tests-frame frame)
                     (with-output-recording-options (output :record recording-p)
  