Text after + in an email address being disregarded in uniqueness check

[Richie (Richie Rich)]

This might be related to the HTTP/500 error we get on our Discourse when using + signs in email addresses depending on the status of the normalize_emails setting:

Users getting Internal Server Error when trying to change email address

Discourse 3.4.0.beta4-dev (5bc7371192). Users are unable to change their email address to a previously used email address. Steps to replicate: Change your account email address to something with a + sign in it, eg. your+name@example.com (The plus sign may be the significant key here, or it may be a red herring) Follow the email prompts to confirm the change Change your email address back to what it was previously, eg. yourname@example.com Follow the email prompts to confirm the cha…