anchor.diff:    (run-hooks *window-scroll-functions* window))
   
   (defun window-wrapping-offset (window)
  -  (unless (variable-value 'truncate-lines :buffer (window-buffer window))
  +  (unless (variable-value 'truncate-lines :default (window-buffer window))
       (return-from window-wrapping-offset 0))
     (let ((offset 0))
       (labels ((inc (arg)
  
positive.code:     (line-offset (window-view-point window) 1)))
  
  (defun %scroll-up-if-wrapping (window)
    (when (and (variable-value 'truncate-lines :buffer (window-buffer window))
               (not (first-line-p (window-view-point window))))
      (let ((charpos-list))
        (map-wrapping-line (line-string (if (start-line-p (window-view-point window))
  
negative.code:      (setq start i)))
  
  (defun %scroll-down-if-wrapping (window)
    (when (variable-value 'truncate-lines :default (window-buffer window))
      (let ((view-charpos (point-charpos (window-view-point window))))
        (line-start (window-view-point window))
        (map-wrapping-line (line-string (window-view-point window))
  