title: Magento: edit quantity and update price of bundle option in quote item
body: <p>I am working with Magento bundle products that contain hidden bundle options that need to have the quantity updated programmatically. A problem arises when the bundle quantity is edited from the shopping cart. I have a button set up to submit the bundle quote item to an updateLineItemAction() method in my own CartController to handle the update of the hidden bundle option.</p>
  
  <p>The updateLineItemAction() method locates the hidden bundle option and assigns the updated quantity to the "selection_qty_X" and "product_qty_X" properties, where X is the ID of the bundle option. Values in the "info_buyRequest" are also updated. After saving the quote item, there's a redirect to the cart to show the updated cart values.</p>
  
  <p>The updated quantity is displayed correctly in the cart, and the hidden bundle option has the correct quantity assigned. The problem is that the bundle item price has not updated to reflect the updated quantity on the hidden bundle option. I did something similar to this in Magento 1.1.x and it worked fine. Doing this now in 1.4.1.2, the price is not automatically updated when the quote item is saved. I've tried saving the quote and the cart again after updating the item, but that doesn't seem to have any effect. </p>
  
  <p>What is the proper way to recalculate the price for a quote item when subitems have had the quantity changed? Is there a better way to change the quantity of a quote item bundle option so that the price of the bundle item is updated correctly?</p>