bug#13949: 24.4.1; `fill-paragraph' should not always put the buffer as modified

[Andreas Röhler]

On 27.03.2016 16:56, Eli Zaretskii wrote:
> > From: Óscar Fuentes <ofv@wanadoo.es>
> > Date: Sun, 27 Mar 2016 05:31:19 +0200
> > Cc: Jaakov <j_k_v@ro.ru>, 13949@debbugs.gnu.org
> >
> > diff --git a/lisp/textmodes/fill.el b/lisp/textmodes/fill.el
> > index 100e2a2..9e1f430 100644
> > --- a/lisp/textmodes/fill.el
> > +++ b/lisp/textmodes/fill.el
> > @@ -804,6 +804,7 @@ fill-paragraph
> >     (interactive (progn
> >                  (barf-if-buffer-read-only)
> >                  (list (if current-prefix-arg 'full) t)))
> > +  (setq h (if (buffer-modified-p) "" (secure-hash 'md5 (current-buffer))))
> >     (or
> >      ;; 1. Fill the region if it is active when called interactively.
> >      (and region transient-mark-mode mark-active
> > @@ -862,7 +863,10 @@ fill-paragraph
> >                        ;; fill-region.
> >                        (fill-region beg end justify)
> >                      (fill-region-as-paragraph beg end justify))))))
> > -     fill-pfx)))
> > +     fill-pfx))
> > +  (when (and (not (string= h ""))
> > +             (string= h (secure-hash 'md5 (current-buffer))))
> > +    (set-buffer-modified-p nil)))
> Thanks, but I'm not sure computing the hash is enough: the functions
> involved in refilling can change text properties, so the test should
> also account for that.

Maybe restrict the notion of changes here to all values, which an 
auto-save would store?