The registration system currently allows a user to register several times using the same email address.

[alegontarz]

Describe the bug

DSpace 9.0
The registration system currently allows a user to register several times using the same email address.

To Reproduce

Steps to reproduce the behavior:

1. Go to https://sandbox.dspace.org/register
2. Register and create an account
3. Go to the page again and type the same e-mail address
4. Observe that the system permits multiple registrations with the identical email address.

Expected behavior

The registration process should validate that the e-mail address is unique and prompt an error if a user attempts to register with an address that is already in use.

[tdonohue]

I've verified this bug on https://sandbox.dspace.org/ by attempting to register the "dspacedemo+admin@gmail.com" email address a second time. The process works and the new registration email is sent. So that seems like a bug.

I'd expect one of the following:

1. The registration process should proceed from the UI, but the forgot password email is sent. As it should recognize this account already exists.
2. Or, the registration process in the UI should fail because the email already exists. (This might be a minor privacy concern though because it'd allow people to see if an email was already registered by entering them in the registration form)

Needs a volunteer.

[jesielviana]

I'm taking a look at this issue. Apparently, it's related to PR 9849