On Sat, Aug 14, 2021 at 11:05:53PM +0200, Emanuel Berg via Users list for the GNU Emacs text editor wrote:
> Gregory Heytings wrote:
> 
> >>> (defvar saved-buffer-read-only)
> >>> (defun delete-whitespace-at-eol ()
> >>>   (interactive)
> >>>   (setq saved-buffer-read-only buffer-read-only)
> >>>   (setq buffer-read-only nil)
> >>>   (save-excursion (replace-regexp " *$" "" nil (point-min) (point-max)))
> >>>   (setq buffer-read-only saved-buffer-read-only))
> >>
> >> OK, but you don't need to store the old value in a global variable...
> >>
> > Of course you do, you need to restore the original value [...]
> 
> But there is still no need to use a global variable...

That's not the point. You perhaps don't want to trample on one. The
let-binding helps you with that. In both cases.

Cheers
 - t