_rsvg_pop_view_box (RsvgDrawingCtx * ctx)
{
    ctx->vb = *((RsvgViewBox *) ctx->vb_stack->data);
    g_free (ctx->vb_stack->data);
    ctx->vb_stack = g_slist_delete_link (ctx->vb_stack, ctx->vb_stack);
}
_rsvg_pop_view_box (RsvgDrawingCtx * ctx)
{
    ctx->vb = *((RsvgViewBox *) ctx->vb_stack->data);
    g_free (ctx->vb_stack->data);
    ctx->vb_stack = g_slist_delete_link (ctx->vb_stack, ctx->vb_stack);
}