bug#60338: [PATCH] Add option to present server changes as diffs

[Eli Zaretskii]

> From: Philip Kaludercic <philipk@posteo.net>
> Date: Sun, 11 Jun 2023 21:33:40 +0000
> 
> +       ((eq confirm 'diff)
> +        (with-current-buffer (get-buffer-create " *Changes*")
> +          (buffer-disable-undo (current-buffer))
> +          (let ((buffer-read-only t))
> +            (diff-mode))
> +          (let ((inhibit-read-only t)
> +                (target (current-buffer)))
> +            (erase-buffer)
> +            (pcase-dolist (`(,path ,edits ,_) prepared)
> +              (with-temp-buffer
> +                (let ((diff (current-buffer)))
> +                  (with-temp-buffer
> +                    (insert-file-contents path)
> +                    (eglot--apply-text-edits edits)
> +                    (diff-no-select path (current-buffer)
> +                                    nil t diff))

Isn't there a better way of presenting the edits in human-readable
form than apply them and then run Diff?  What format is used by the
server itself to send the edits?

Besides, this assumes the 'diff' command is available, which is not
portable -- one more reason not to go that way, or at leas provide an
alternative.