Magento SOAP (v1) API causes fatal error getSelect() after completed order

Question

I'm trying to complete my software which interacting with the Magento API and another external API (REST). In this project I forwarding the orders of the other shop system towards Magento and I'm able to create a order (yeha!).

Unfortunately, Magento seems to cause an fatal error after the successful order. That's a problem because I've to convert about hundrets orders...

Fatal error: Uncaught SoapFault exception: [SOAP-ENV:Server] Call to a member function getSelect() on a non-object in /var/orders.php:280
Stack trace:
#0 /var/orders.php: SoapClient->__call('call', Array)
#1 /var/orders.php: SoapClient->call('6ceb613d278de9e...', 'cart.order', Array)
#2 /var/orders.php: complete_order(Array, 3)
#3 /var/orders.php: new_orders(Object(mysqli))

Does anybody have any idea how to solve that?

The involved line in the PHP file:

    $result = $client->call($session, 'cart.info', $shopping_cart_id);

The whole PHP code:

function complete_order($val,$i=1) {
    if($i == 3) {
    $client = new SoapClient(MAGENTO_HOST.'/api/soap/?wsdl');
    $session = $client->login(MAGENTO_API_USER, MAGENTO_API_KEY);

    # Choose a store id 
    $store_id = $client->call($session, 'category.currentStore', MAGENTO_STORE_ID);

    # Create a new shopping cart
    $shopping_cart_id = $client->call( $session, 'cart.create', $store_id );

    # Add products to cart #
    $product_for_cart = array(
        array(
            "sku" => "TOPP19600",
            "qty" => 2,
            "options" => null
        ),
        array(
            "sku" => "TOPP19601",
            "qty" => 1,
            "options" => null
        )
    );

    $val['items'] = $product_for_cart;

    foreach($val['items'] AS $item) {
        $filters = array( 
            'status' => array( '=' => 1 ),  
            'sku' => array( '=' => $item['sku']), 
        ); 
        $result = $client->call($session, 'catalog_product.list', array($filters,$store_id));
        if($result != NULL AND count($result) > 0) {
            $product_for_cart[] = array('product_id' => $result[0]['product_id'], 'qty' => $item['qty']);
        } else {
            # unknown product found #
            echo('Unknown product'); 
        }
    }

    # Customer information (as guest) #
    $customer = array(
    'mode' => 'guest',
    'firstname' => $val['invoice_address']['firstname'],
    'lastname' => $val['invoice_address']['lastname'],
    'email' => $val['invoice_address']['email'],
    'website_id' => 0,
    'store_id' => 0,
    'group_id' => 0,
    'dob' => date('d.m.Y',$val['created_at']),
    'confirmation' => 1
    );

    $resultCustomerSet = $client->call($session, 'cart_customer.set', array($shopping_cart_id, $customer, $store_id) );

    // Set customer addresses, for example guest's addresses
    $arrAddresses = array(
        array(
            "mode" => "shipping",
            "firstname" => "testFirstname",
            "lastname" => "testLastname",
            "company" => "testCompany",
            "street" => "testStreet",
            "city" => "testCity",
            "region" => "testRegion",
            "postcode" => "testPostcode",
            "country_id" => "id",
            "telephone" => "0123456789",
            "fax" => "0123456789",
            "is_default_shipping" => 0,
            "is_default_billing" => 0
        ),
        array(
            "mode" => "billing",
            "firstname" => "testFirstname",
            "lastname" => "testLastname",
            "company" => "testCompany",
            "street" => "testStreet",
            "city" => "testCity",
            "region" => "testRegion",
            "postcode" => "testPostcode",
            "country_id" => "id",
            "telephone" => "0123456789",
            "fax" => "0123456789",
            "is_default_shipping" => 0,
            "is_default_billing" => 0
        )
    );

    $add_product_to_cart = $client->call($session,"cart_product.add",array($shopping_cart_id, $product_for_cart));

    $resultCustomerAddresses = $client->call($session,"cart_customer.addresses",array($shopping_cart_id, $arrAddresses, $store_id));

    $choose_shipping_method = $client->call($session, 'cart_shipping.method', array($shopping_cart_id, 'pl_store_pickup_kostenlose_selbstabholung_w_hrend_den_gesch_ftszeiten_sie_erhalten_eine_e_mail_benachrichtigung_sobald_ihre_bestellung_zur_abholung_bereit_liegt__jawolle_rheinstr_29_66113_saarbr_cken'));

    $resultPaymentMethod = $client->call($session,'cart_payment.method',array($shopping_cart_id, $paymentMethod = array('method' => 'bankpayment')));

    # Finishing order # 
    $result = $client->call($session, 'cart.info', $shopping_cart_id);

    $client->endSession($session);

Answer 1

I understand what's wrong....

I have a plugin (TrustedShop) who use an observer on 'checkout_type_onepage_save_order_after'

I remove in the plugin the part :

        <checkout_type_onepage_save_order_after>
           <observers>
                <buyerprotect>
                    <type>singleton</type>
                    <class>Symmetrics_Buyerprotect_Model_Observer</class>
                    <method>registerTsSoapModel</method>
                </buyerprotect>
            </observers>
        </checkout_type_onepage_save_order_after>

And it's fine...