My magento has two warehouses, and the cart cannot have two products with different warehouses. I check this with an observer. But, I have a problem:
A logged user has in his cart a product with the warehouse A. And he logs out. After, a guest user add to his cart a product with the warehouse B. And finally, the first user is logged again and in his cart appears a product with A and other with B.
How can I resolve it? The product B should not appear in the cart in the last step.