anchor.diff:  
   (defvar *window-sufficient-width* 150)
   (defvar *scroll-recenter-p* t)
  +(defvar *window-scroll-functions* nil)
   
   (defvar *modeline-default-format*
     (list 'modeline-read-only-p
  
positive.code: (export '(*modeline-default-format*
            *window-sufficient-width*
            *scroll-recenter-p*
            modeline-read-only-p
            modeline-modified-p
            modeline-name
  
negative.code:   (when (< (buffer-nlines (window-buffer window))
             (window-vtop-linum window))
      (setf (window-vtop-linum window)
            (buffer-nlines (window-buffer window))))
    (dolist (fun *window-scroll-functions*)
      (funcall fun window)))
  
  (defun window-wrapping-offset (window)
    (unless (buffer-truncate-lines (window-buffer window))
  