app/code/core/Mage/Sales/Model/Quote  Item.php

public function setProduct($product)    {        if ($this->getQuote()) {            $product->setStoreId($this->getQuote()->getStoreId());            $product->setCustomerGroupId($this->getQuote()->getCustomerGroupId());        }        $this->setData('product', $product)            ->setProductId($product->getId())            ->setProductType($product->getTypeId())            ->setSku($this->getProduct()->getSku())            ->setName($product->getName()."|S") // this line            ->setWeight($this->getProduct()->getWeight())            ->setTaxClassId($product->getTaxClassId())            ->setBaseCost($product->getCost())            ->setIsRecurring($product->getIsRecurring())        ;        if ($product->getStockItem()) {            $this->setIsQtyDecimal($product->getStockItem()->getIsQtyDecimal());        }        Mage::dispatchEvent('sales_quote_item_set_product', array(            'product' => $product,            'quote_item'=>$this        ));//        if ($options = $product->getCustomOptions()) {//            foreach ($options as $option) {//                $this->addOption($option);//            }//        }        return $this;    }