Check email when creating a user in drupal 8

Check email when creating a user in drupal 8

When visiting a contribution page as an anonymous user & it is possible to create a new Drupal 8 user, there is currently no correct validation on email address within the profile form.

So when using an email address of an existing Drupal 8 user in the profile form and you continue on the confirmation page you will be redirected to the home page instead of for example the online payment page.

I noticed that in the function "checkUserNameEmailExists" the variable "$emailName" does not match the key in the "$params" array.