Topic: Item is not getting update in via sales invoice api

Hi .

I have followed the code from Sales_Test.php  as below.

     // Write back
        $response = $client->put('/modules/api/sales/' . $id . '/' . ST_SALESINVOICE, array(
            'headers' => TestEnvironment::headers(),
            'form_params' => array(
                'trans_type' => ST_SALESINVOICE,
                'ref' => $ref, // TODO Ideally the api would default this and return.
                'comments' => 'new comments',
                'order_date' => '02/03/2013',

                'delivery_date' => '04/05/2013',
                'cust_ref' => 'cust_ref',
                'deliver_to' => 'new deliver_to',
                'delivery_address' => 'new delivery_address',
                'phone' => 'new phone',
                'ship_via' => 'new ship_via',
                'location' => 'DEF',
                'freight_cost' => '0',
                'customer_id' => '2',
                'branch_id' => '2',
                'sales_type' => '1',
                'dimension_id' => '0',
                'dimension2_id' => '0',

//                 'items' => array(
//                     0 => array(
//                         'stock_id' => 'TEST_ITEM',
//                         'qty' => '2',
//                         'price' => '3',
//                         'discount' => '0',
//                         'description' => 'new description'
//                     )
//                 ),
            )
        ));

        $this->assertEquals('200', $response->getStatusCode());
        $result = $response->getBody();
        $result = json_decode($result);

But if you can see  ITEM CODE is disabled in the sample code.
I've tried to enable this code and update invoice.
But its now working as it should be . The error is ( THIS ITEM IS ALREADY ATTACHED TO THE INVOICE ) which is correct. All i need to update this product's price or details. Which it should basically just let it update.

I did further study . I found out it it always use add_to_order() function

    if (isset($info["items"])) {
        foreach($info['items'] as $item) {
            add_to_order($cart, $item['stock_id'], $item['qty'], $item['price'], $item['discount'], $item['description']);
        }
    }

So.. basically its not working . And i guess that is why item editing part was disabled in sample code.

Is there any new update for this ?