mysql4-upgrade-1.7.12-1.7.13.php

<?php
/**
 * TecRepair Installator
 *
 * @category    Kirchbergerknorr
 * @package     Kirchbergerknorr_TecRepair
 * @author      Aleksey Razbakov <[email protected]>
 * @copyright   Copyright (c) 2014 kirchbergerknorr GmbH (http://www.kirchbergerknorr.de)
 * @license     http://opensource.org/licenses/osl-3.0.php  Open Software License (OSL 3.0)
 */

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

$product = Mage::getModel('catalog/product')->loadByAttribute('sku', 'product_sku');

$image = $Mage::getBaseDir('media') . DS ."image.png";

if (is_file($image))
{
    $product->addImageToMediaGallery($image, array ('image', 'small_image', 'thumbnail'), false, false);
    $product->save();
}

$installer->endSetup();