bug#35739: Bad signature from GNU ELPA

[Eli Zaretskii <eliz@gnu.org>]

> From: Richard Copley <rcopley@gmail.com>
> Date: Tue, 14 May 2019 23:26:27 +0100
> Cc: 35739@debbugs.gnu.org
> 
> Thanks, that seems to be it: the attached patch gets rid of the bug (but obviously isn't TRT).
> 
> diff --git a/lisp/url/url-handlers.el b/lisp/url/url-handlers.el
> index e35d999e0f..f8af2ce88c 100644
> --- a/lisp/url/url-handlers.el
> +++ b/lisp/url/url-handlers.el
> @@ -334,11 +334,11 @@ url-insert-buffer-contents
>        (when replace
>          (delete-region (point-min) start)
>          (delete-region (point) (point-max)))
> -      (unless (cadr size-and-charset)
> -        ;; If the headers don't specify any particular charset, use the
> -        ;; usual heuristic/rules that we apply to files.
> -        (decode-coding-inserted-region (point-min) (point) url
> -                                       visit beg end replace))
> +      ;; (unless (cadr size-and-charset)
> +      ;;   ;; If the headers don't specify any particular charset, use the
> +      ;;   ;; usual heuristic/rules that we apply to files.
> +      ;;   (decode-coding-inserted-region (point-min) (point) url
> +      ;;                                  visit beg end replace))
>        (let ((inserted (car size-and-charset)))
>          (when (fboundp 'after-insert-file-set-coding)
>            (let ((insval (after-insert-file-set-coding inserted visit)))

I don't see how disabling decoding could make sense, can you explain?
What does this code do on GNU/Linux?