bug#74902: 31.0.50; Segfault when deleting frames

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

Robert Pluim <rpluim@gmail.com> writes:
> If you do find a reproducer, then based on the trace above I think the
> following should fix it:
>
> diff --git a/src/frame.c b/src/frame.c
> index f6053fca3ef..ff9e1d24ea1 100644
> --- a/src/frame.c
> +++ b/src/frame.c
> @@ -2281,7 +2281,9 @@ delete_frame (Lisp_Object frame, Lisp_Object force)
>    delete_all_child_windows (f->root_window);
>    fset_root_window (f, Qnil);
>  
> +  block_input();
>    Vframe_list = Fdelq (frame, Vframe_list);
> +  unblock_input();
>    SET_FRAME_VISIBLE (f, 0);
>  
>    /* Allow the vector of menu bar contents to be freed in the next

From what I can tell (my reproducer isn't 100% effective), this does
indeed fix the issue. Thanks!