plataformatec/devise — Issue #1558: Unable to override sessions_controller#create to change the logged in user
Author: Altonymous
Created: 2012-01-09 22:47:26+00:00
State: open

Please see the following post for more information:
http://stackoverflow.com/questions/8012810/rails-3-devise-issue-overriding-login

The problem occurs on a shared computer where 'User A' is currently logged in, and 'User B' comes in after him and attempts to login while 'User A' is still logged in. The easiest way to reproduce this issue is to open two tabs and navigate to the login page on both of them. Then login on the first tab with 'User A' and while logged in attempt to login with 'User B' on the second tab. you will notice that 'User B' is automatically logged in as 'User A' The expected behavior is that 'User A's' session will be logged out and 'User B' will be logged in.

If you want to see the proper behavior just try this with Google Apps.