'checkout as guest' work same as 'register' with auto generated password

Question

On onepage-checkout page there are three methods to check out.

How checkout as guest method work same register method with auto generated password?

Answer 1

I would suggest observing customer_register_success event and doing something like this:

$customer = $observer->getEvent()->getData('customer');
/* TODO: check that registration type is 'guest'. Otherwise you overwrite inserted password */
$customer->setPassword(_your_generated_password_here_)->save();