REDRAW_BORDER_U
case REDRAW_BORDER_L|REDRAW_BORDER_R|REDRAW_BORDER_U|REDRAW_BORDER_D:
case REDRAW_BORDER_L|REDRAW_BORDER_R|REDRAW_BORDER_U:
case REDRAW_BORDER_L|REDRAW_BORDER_U|REDRAW_BORDER_D:
case REDRAW_BORDER_L|REDRAW_BORDER_U:
case REDRAW_BORDER_R|REDRAW_BORDER_U|REDRAW_BORDER_D:
case REDRAW_BORDER_R|REDRAW_BORDER_U:
case REDRAW_BORDER_U|REDRAW_BORDER_D:
case REDRAW_BORDER_U:
if (mask & (REDRAW_BORDER_U|REDRAW_BORDER_D)) {
mask |= REDRAW_BORDER_U;
mask |= REDRAW_BORDER_U;