>
> Can you look up the line numbers against your source tree to see which
> code segment was active when the error happened?


Yes, it was the latter, i.e.

      if (update_miniwindow_p)
{
 Lisp_Object mini_window = FRAME_MINIBUF_WINDOW (sf);

 displayed_buffer = XBUFFER (XWINDOW (mini_window)->contents);
17526 : internal_condition_case_1 (redisplay_window_1, mini_window,
    list_of_error,
    redisplay_window_error);
}

Thanks!
George