<?php
/**
 * Magento
 *
 * NOTICE OF LICENSE
 *
 * This source file is subject to the Open Software License (OSL 3.0)
 * that is bundled with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://opensource.org/licenses/osl-3.0.php
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@magentocommerce.com so we can send you a copy immediately.
 *
 * DISCLAIMER
 *
 * Do not edit or add to this file if you wish to upgrade Magento to newer
 * versions in the future. If you wish to customize Magento for your
 * needs please refer to http://www.magentocommerce.com for more information.
 *
 * @category    Mage
 * @package     Mage_Downloadable
 * @copyright   Copyright (c) 2012 Magento Inc. (http://www.magentocommerce.com)
 * @license     http://opensource.org/licenses/osl-3.0.php  Open Software License (OSL 3.0)
 */

/** @var $installer Mage_Catalog_Model_Resource_Setup */
$installer = $this;

$applyTo = explode(',', $installer->getAttribute(Mage_Catalog_Model_Product::ENTITY, 'group_price', 'apply_to'));
if (!in_array(Mage_Downloadable_Model_Product_Type::TYPE_DOWNLOADABLE, $applyTo)) {
    $applyTo[] = Mage_Downloadable_Model_Product_Type::TYPE_DOWNLOADABLE;
    $installer->updateAttribute(Mage_Catalog_Model_Product::ENTITY, 'group_price', 'apply_to', implode(',', $applyTo));
}