unique email is not enforced

[Denis-de-Bernardy]

When you create (or edit) a user in the admin area, email uniqueness is not enforced. See also: #1626

[Denis-de-Bernardy]

the patch also makes the error codes consistent with those from the registration form.

[Nicholas91]

Tested on Ubuntu/XAMPP.

[Denis-de-Bernardy]

see also: #4170 and #9564

[ryan]

(In [10990]) Enforce unique email addresses. Props Denis-de-Bernardy. fixes #9563

[MichaelH]

Interesting consequences:

​http://wordpress.org/support/topic/272530

[Denis-de-Bernardy]

Tricky... I'm pretty certain it's extremely rare, though, due to the fact that the registration form has always enforced this. Only an admin could possibly create a user with a dup email, and that was more of a bug than anything else.

Imo we leave things as they are and let the rare admins that have dup users delete them -- WP does a good job at merging a user into another one when a user gets deleted.

[mattcaron]

I'm reopening this because it introduces a regression.

While the initial intent (not allowing multiple user registration) is reasonable, it introduces a problem as follows:

1. Set up WP
2. An admin user is created
3. User's email is set to my email address
4. I want my posts to show up as from me.
5. So I create a new user (me) with my address.

Before this fix, this worked. After this fix, it stopped working. So, today, when I did a fresh install, I had to enter a bogus email and then change it in the DB backend.

Another option would be to be able to change the default admin account's username, but that can be problematic - better to just allow the creation of multiple accounts with the same address from the admin panel (perhaps with warning).

[scribu]

Please open a new ticket and leave this one as fixed in 2.8.