Re: font-lock-fontify-block

[Gregory Heytings]

> > Because font-lock-fontify-region changes point.  It seems that it 
> > doesn't change mark, but I'm not sure it never will, so I've used 
> > save-mark-and-excursion just in case.
>
> It never will so you can use `save-excursion`.

Okay, thanks:

(defun font-lock-update (&optional arg)
  "Updates the syntax highlighting in this buffer.
Refontify the accessible portion of this buffer, or enable Font Lock mode
in this buffer if it is currently disabled.  With prefix ARG, toggle Font
Lock mode."
  (interactive "P")
  (save-excursion
    (if (and (not arg) font-lock-mode)
        (font-lock-fontify-region (point-min) (point-max))
      (font-lock-unfontify-region (point-min) (point-max))
      (font-lock-mode 'toggle))))
(global-set-key (kbd "C-x x f") 'font-lock-update)

The "C-x x f" binding is less convenient than the "M-o M-o" one, but this 
regression is compensated by the fact that font-lock-update works 
correctly, unlike font-lock-fontify-block.  It is also more general, as it 
can be used to toggle Font Lock mode.  All in all, it seems to me that 
this is a progress.