Log in user with unconfirmed email

Question

During guest checkout, when customer places order, he gets two emails - first one is email confirmation ("Please activate your account") and second one - information about order.

Is there any way to programatically log in this new user on a site directly after the checkout? (so after the checkout he can go to customer/account without having to log in)

In Mage_Checkout_Model_Type_Onepage, there is function:

protected function _involveNewCustomer()
{
    $customer = $this->getQuote()->getCustomer();
    if ($customer->isConfirmationRequired()) {
        $customer->sendNewAccountEmail('confirmation', '', $this->getQuote()->getStoreId());
        $url = Mage::helper('customer')->getEmailConfirmationUrl($customer->getEmail());
        $this->getCustomerSession()->addSuccess(
            Mage::helper('customer')->__('Account confirmation is required. Please, check your e-mail for confirmation link. To resend confirmation email please <a href="%s">click here</a>.', $url)
        );

        // WHAT SHOULD I PUT HERE TO LOGIN CUSTOMER?
        // I tried: $this->getCustomerSession()->loginById($customer->getId()); , but it doesn't work and just redirects to cart page

    } else {
        $customer->sendNewAccountEmail('registered', '', $this->getQuote()->getStoreId());
        $this->getCustomerSession()->loginById($customer->getId());
    }
    return $this;
}

Answer 1

Here how you can login a customer automatically

Mage::getSingleton('customer/session')->setCustomerAsLoggedIn($customer);

But I don't understand something in your logic.
You are requiring the customers to validate their account after creating it, but if a user creates an account while in the checkout process then you don't want him to confirm his e-mail.

If you won't to skip the e-mail validation step just edit the setting in System->Configuration->Customer configuration.

Answer 2

You might want to have a look at how it's done in the core of Magento, what you'll find is this :

$session = Mage::getSingleton('customer/session');
$session->login('username', 'password');
$session->setUsername('username');

And add in the information you want.