anchor.diff:                                     region)
     (declare (ignorable region))
     (let ((cursor (stream-text-cursor stream)))
  -    (if (cursor-visibility cursor)
  +    (if (cursor-state cursor)
   	(progn
   	  ;; Erase the cursor so that the subsequent flip operation will make a
   	  ;; cursor, whether or not the next-method erases the location of the
  
positive.code: 				(+ x width) (+ y height)
  				:filled t
  				:ink +foreground-ink+
  				))
  	(:erase (draw-rectangle* (sheet-medium (cursor-sheet cursor))
  				 x y
  				 (+ x width) (+ y height)
  				 :filled t
  				 :ink +background-ink+))))))
  
  ;;; Standard-Text-Cursor class
  
  
negative.code:    (x :initform 0 :initarg :x-position)
     (y :initform 0 :initarg :y-position)
     (width :initform 8)
     (cursor-active :initform T  ;; XXX what does "cursor is active" mean?                  
                    :accessor cursor-active)
     (cursor-state :initform nil
                   :accessor cursor-state)))
  
  (defgeneric cursor-height (cursor))
  
  