Re: [Emacs-diffs] emacs-26 59e8533 1/3: Add save-match-data to abbreviate-file-name (Bug#32201)

[Noam Postavsky]

On Tue, 16 Oct 2018 at 21:50, Stefan Monnier <address@hidden> wrote:
>
> > @@ -1929,7 +1929,7 @@ started Emacs, set `abbreviated-home-dir' to nil so 
> > it will be recalculated)."
> >                        (save-match-data
> >                          (string-match "^[a-zA-`]:/$" filename))))
> >                 (equal (get 'abbreviated-home-dir 'home)
> > -                      (expand-file-name "~")))
> > +                      (save-match-data (expand-file-name "~"))))
> >         (setq filename
> >               (concat "~"
> >                       (match-string 1 filename)
>
> Wouldn't it better to read (match-string 1 filename) earlier?
> `save-match-data` is a costly operation compared to (match-string
> 1 filename), so it doesn't make much sense to use it everywhere
> between the match and the final (match-string 1 filename).

Yeah, I think I kind of added it mindlessly, following the
save-match-data in the previous clause.