invalid check of the cart form id

uc_dependent_attributes assumes that the cart form id always contains a node ID. Although this is usually the case, ubercart supports adding the node id, and not adding the node id.

function theme_uc_product_add_to_cart($node, $teaser = 0, $page = 0) {
  $output = '<div class="add-to-cart">';
  if ($node->nid) {
    $output .= drupal_get_form('uc_product_add_to_cart_form_'. $node->nid, $node);
  }
  else {
    $output .= drupal_get_form('uc_product_add_to_cart_form', $node);
  }
  $output .= '</div>';
  return $output;
}

Here's a patch to check for 'uc_product_add_to_cart_form' rather than 'uc_product_add_to_cart_form_'