$inv->add_grn_to_trans($line->grn_item_id, $line->po_detail_rec, $line->stock_id,
            $line->item_description, $line->receive_qty, 0, $line->receive_qty,
            $line->price, $line->price, true, get_unit_cost($line->stock_id), '');

function add_grn_to_trans($grn_item_id, $po_detail_item, $item_code, $item_description, 
        $qty_recd, $prev_quantity_inv, $this_quantity_inv, $order_price, $chg_price, 
        $std_cost_unit=null, $gl_code='')
    {
        $this->grn_items[$grn_item_id] = new grn_item($grn_item_id, $po_detail_item, 
            $item_code, $item_description, $qty_recd, $prev_quantity_inv, $this_quantity_inv, 
            $order_price, $chg_price, $std_cost_unit, $gl_code, $this->tax_included);

        $this->src_docs = find_src_invoices($this);

        unset($this->tax_overrides); // cancel tax overrides after cart change
        return 1;
    }