Ubercart

Came across a weird rounding problem this morning.
Had an order of $3.98 and a line item of -$3.98 (from gift certificate module)
uc_order_get_total() returned 4.4408920985006E-16 instead of zero.

function uc_order_get_total($order, $products_only = FALSE) {
  $total = 0;

  if (is_array($order->products)) {
    foreach ($order->products as $product) {
      $total += $product->price * $product->qty;
    }
  }

  if ($products_only) {
    return $total;
  }

  $total += uc_line_items_calculate($order);

  $result = module_invoke_all('order', 'total', $order, NULL);
  foreach ($result as $key => $value) {
    $total += $value;
  }
  return $total;
}

Been checking all values in db plus added a ton of drupal_set_message() to debug, but everything seems correct but the addition result... (no problems with uc_line_items_calculate())

Seems to me it's a PHP problem, had to insert this line before returning the total to fix it.

$total = round($total,2);

That being said, I'm not really fan of this fix and I'm a bit scared to overwrite it on next UC update. Any opinion/advice on this ?

Thanks