bug#70311: Crash when dnd-indicate-insertion-point is non-nil

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

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Po Lu <luangruo@yahoo.com>
>> Cc: gregsexton@gmail.com,  70311@debbugs.gnu.org
>> Date: Sat, 13 Apr 2024 20:28:14 +0800
>> 
>> Eli Zaretskii <eliz@gnu.org> writes:
>> 
>> > So you think the suggested band-aid is the best we can currently do to
>> > prevent crashes in those cases?
>> 
>> Yes, unfortunately.
>
> Does the band-aid below look OK to you?
>
> diff --git a/lisp/dnd.el b/lisp/dnd.el
> index 89652d3..de1c58a 100644
> --- a/lisp/dnd.el
> +++ b/lisp/dnd.el
> @@ -149,8 +149,13 @@ dnd-handle-movement
>                  (with-selected-window window
>                    (scroll-down 1))))))))
>        (when dnd-indicate-insertion-point
> -        (ignore-errors
> -          (goto-char (posn-point posn)))))))
> +        (let ((pos (posn-point posn)))
> +          ;; We avoid errors here, since on some systems this runs
> +          ;; when waiting_for_input is non-zero, and that aborts on
> +          ;; error.
> +          (if (and pos (<= (point-min) pos (point-max)))
> +              (goto-char pos)
> +            pos))))))

Yes, please install.  Thanks.