fix a bug in fill_style_read

    return fill_style_read_hatch(ctx, expr_get_list_tail(expr), style);

  }

  if (expr_is_value(expr)) {

  if (expr_is_value(expr) || expr_is_list(expr)) {

    return fill_style_read_solid(ctx, expr, style);

  }

  return errorf(

      ERROR,

      "invalid <fill-style>; expected a color or one of (none), "

      "invalid <fill-style>; expected a color, 'hatch' or 'none', "

      "but got: '{}'",

      expr_inspect(expr));

}