Read further down. It's about the merging of an SSO account with an email account, where the email address is the same. django-allauth is an excellent python p

Read further down. It's about the merging of an SSO account with an email account, where the email address is the same. django-allauth is an excellent python package, for example, that has put a lot of effort into such things but I can see how plenty of websites roll their own auth code and make a mess of the complexity that is user accounts.