bug#31373: 26.1; frame-list-z-order segfaults on initial daemon frame

[Eli Zaretskii]

> Date: Mon, 07 May 2018 08:26:01 +0200
> From: martin rudalics <rudalics@gmx.at>
> 
> -         if (XFRAME (frame)->output_data.x->parent_desc == children[i]
> -             || FRAME_OUTER_WINDOW (XFRAME (frame)) == children[i])
> +            if (FRAME_X_P (frame)
> +                && (XFRAME (frame)->output_data.x->parent_desc == children[i]
> +                    || FRAME_OUTER_WINDOW (XFRAME (frame)) == children[i]))
> 
> Thank you.  Eli, I think Noam should push this to 26.1, if still
> possible.

Why?  The workaround is very simple: don't call that function in a
daemon session that has no GUI frames.