bug#64415: [PATCH] Use first match in dir-local `auto-mode-alist'

[Stefan Monnier via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

> * lisp/files.el (set-auto-mode): Reverse the reversed alist.
> ---
>  lisp/files.el | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/lisp/files.el b/lisp/files.el
> index 148f47cbc97..fc3b47082ea 100644
> --- a/lisp/files.el
> +++ b/lisp/files.el
> @@ -3396,8 +3396,9 @@ we don't actually set it to the same mode the buffer already has."
>      (unless done
>        (with-demoted-errors "Directory-local variables error: %s"
>  	;; Note this is a no-op if enable-local-variables is nil.
> -        (let* ((mode-alist (cdr (hack-dir-local--get-variables
> -                                 (lambda (key) (eq key 'auto-mode-alist))))))
> +        (let* ((mode-alist (reverse (cdr (hack-dir-local--get-variables
> +                                          (lambda (key)
> +                                            (eq key 'auto-mode-alist)))))))
>            (setq done (set-auto-mode--apply-alist mode-alist
>                                                   keep-mode-if-same t)))))
>      (and (not done)

AFAICT the reversal happens within `dir-locals-collect-mode-variables`.
I think this is a bug in `hack-dir-local--get-variables`: it should return the
vars in the same order as found in the file.


        Stefan