anchor.diff:              point-y)))
   
   (defun screen-display-lines (screen redraw-flag buffer view-point cursor-point)
  -  (let ((disp-line-function
  -         (if (variable-value 'truncate-lines :buffer buffer)
  -             #'screen-display-line-wrapping
  -             #'screen-display-line))
  -        (wrap-lines (screen-wrap-lines screen))
  -        (left-width (screen-left-width screen)))
  +  (let* ((truncate-lines (variable-value 'truncate-lines :default buffer))
  +         (disp-line-function
  +          (if truncate-lines
  +              #'screen-display-line-wrapping
  +              #'screen-display-line))
  +         (wrap-lines (screen-wrap-lines screen))
  +         (left-width (screen-left-width screen)))
       (setf (screen-wrap-lines screen) nil)
       (let* ((visual-cursor-x 0)
              (visual-cursor-y (count-lines view-point cursor-point))
  
positive.code:                                  point-x
                                   y
                                   str/attributes)))
                       (when (variable-value 'truncate-lines :buffer buffer)
                         (let ((offset (- y2 y)))
                           (cond ((< 0 offset)
                                  (setf redraw-flag t)
                                  (dotimes (_ offset)
                                    (push i (screen-wrap-lines screen))))
                                 ((and (= offset 0) (find i wrap-lines))
                                  (setf redraw-flag t))))
                         (setf y y2))))
                    (t
                     (fill (screen-old-lines screen) nil :start i)
                     (charms/ll:wmove (screen-%scrwin screen) y 0)
  
negative.code:             :for left-str/attr :across (screen-left-lines screen)
              :while (< y (screen-height screen))
              :do (cond
                    ((and (null left-str/attr)
                          (not redraw-flag)
                          (not (null str/attributes))
                          #1=(aref (screen-old-lines screen) i)
  