else BackColor(blackColor);
void do_scroll(void *frontend, int topline, int botline, int lines) {    Session *s = frontend;    Rect r;    RgnHandle update;    /* FIXME: This is seriously broken on Original QuickDraw.  No idea why. */    SetPort(s->window);    if (HAVE_COLOR_QD())	PmBackColor(DEFAULT_BG);    else	BackColor(blackColor);    update = NewRgn();    SetRect(&r, 0, topline * s->font_height,	    s->term->cols * s->font_width, (botline + 1) * s->font_height);    ScrollRect(&r, 0, - lines * s->font_height, update);    /* XXX: move update region? */    InvalRgn(update);    DisposeRgn(update);}