Double aliasses

if(!empty($product->product_alias)){
			$query = 'SELECT product_id FROM '.hikashop_table('product').' WHERE product_alias='.$this->db->Quote($product->product_alias);
			$this->db->setQuery($query);
			$product_with_same_alias = $this->db->loadResult();
			if($product_with_same_alias && (empty($product->product_id) || $product_with_same_alias!=$product->product_id)){
				$app->enqueueMessage(JText::_( 'ELEMENT_WITH_SAME_ALIAS_ALREADY_EXISTS' ), 'error');
				JRequest::setVar( 'fail', $product  );
				return false;
			}
		}

if($config->get('alias_auto_fill', 1) && empty($product->product_alias) && !empty($product->product_name)) {
			$this->addAlias($product);
			// add a letter at the beginning of the alias to avoid issues when the alias of a product starts with a number
			if($config->get('sef_remove_id', 0) && (int)$product->alias > 0)
				$product->alias = $config->get('alias_prefix', 'p') . $product->alias;
			$product->product_alias = $product->alias;
			unset($product->alias);
		}