The public user is a kind of a magic user. 

When a unkown user enters your webshop and order some products. He/She has to fill in some basic information (like name, adress, country etc). Odoo will then create an user with the appropiate information and will go to the payment provider. After payment is succesfull the sale is confirmed.

But what about recurring customers, how can they login? If I use the login from the website they will go to the portal instead of the website (this is confusing for most customers). Also when a visitor creates a new account through the login link, it will give an error (500 error about no rights for this user). I can solve this by making a change in the template, but I don't know if this is necessary, or that I'm doing something wrong. 

Basically what I want is how can a user login with his/her credentials and stays in the website, and he/she doesn't have to fill in all the information when he/she orders some products. Also the registration should be working without going to the portal.

But how do I have to configure the correct rights/settings for make this possible?