anchor.diff:  ;;; - (SETF OUTPUT-RECORD-START-CURSOR-POSITION) does not affect the
   ;;; bounding rectangle. What does it affect?
   ;;;
  +;;; - How should (SETF OUTPUT-RECORD-POSITION) affect the bounding
  +;;; rectangle of the parent? Now its bounding rectangle is accurately
  +;;; recomputed, but it is very inefficient for table formatting. It
  +;;; seems that CLIM is supposed to keep a "large enougn" rectangle and
  +;;; to shrink it to the correct size only when the layout is complete
  +;;; by calling TREE-RECOMPUTE-EXTENT.
  +;;;
  +;;; - Computation of the bounding rectangle of lines ignores
  +;;; LINE-STYLE-CAP-SHAPE.
   
   ;;; Bug: (SETF OUTPUT-RECORD-POSITION) returns the record instead of
   ;;; the position. It is useful for debugging, but it is wrong.
  
positive.code:                                    (+ max-y border))))))
  
  (def-grecording draw-polygon (coord-seq closed filled)
    ;; FIXME !!!
    ;; If LINE-STYLE-JOINT-SHAPE is :MITTER, then the bb is larger than
    ;; these numbers by (LINE-THICKNESS / (sin (angle / 2))),
    ;; which is larger than LINE-THICKNESS
    (with-transformed-positions (transform coord-seq)
       (loop for (x y) on coord-seq by #'cddr
             minimize x into min-x
             minimize y into min-y
             maximize x into max-x
  
negative.code: ;;;
  ;;; - Scrolling does not work correctly. Region is given in "window"
  ;;; coordinates, without bounding-rectangle-position transformation.
  ;;; (Is it still valid?)
  ;;;
  ;;; - Redo setf*-output-record-position, extent recomputation for
  ;;; compound records
  