problem unsetting quote (cart), data is not saved

Question

I need to save quoteId and unset quote (cart) data in session clicking a button when I'm is in the cart, then after performing other operations (for example, I buy some items) I would like to click another button and restore previous cart using quoteId.

I've correctly got quoteId from session using Mage::getSingleton('checkout/session')->getQuoteId();

Then I've tried to unset quote using

$quote = Mage::getModel('sales/quote')->load($quoteId);
$quote->setIsActive(false); //tried setIsActive(0) too
$quote->save();
Mage::getSingleton('checkout/session')->setQuoteId(null);

but unfortunately I still have a filled cart, in fact if I change page and then I come back to my cart I can see it (I expect that it will be empty after unset...), and on my database I can see is_active = 1 for this quote.

What I've done wrong? Can you please help me figuring out how to solve this issue?

Then, do you know how to load/restore quote from database and set it in session, so I can see it in frontend cart?

Answer 1

I'm adding this as an answer for the sake of completeness...

You are missing the brackets for the function call to sale. $quote->save(); is missing the brackets to call the function as opposed to accessing a public member.