I was seeing the following in my console:
```
/home/vagrant/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/devise-3.2.4/app/controllers/devise_controller.rb:9: warning: `*' interpreted as argument prefix
/home/vagrant/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/devise-3.2.4/app/controllers/devise_controller.rb:10: warning: `*' interpreted as argument prefix
```
This change silences this warning.
after_confirmation_path_for checks whether the user already signed in
by calling signed_in? after confirmation succeeded.
Since it was called without scope specification, the user treated as
signed in inappropriately when the user signed in as another resource
(such as 'admin').
Only execute the `SessionsController#destroy` if there is a signed in
user, otherwise it will raise
`ActionController::InvalidAuthenticityToken`.
Fixes#2934.
If you want to add a new behavior to your devise
controllers but you don't want to override devise's
default workflow, just pass a block around resource.
This would give you for example, the ability to
trigger background jobs after user signs in.
For #2627
When allow_unconfirmed_access_for > 0, users may
be already signed in at the time they confirm
their account. Consequently, the default
confirmation should be compatible with this
possibility. Additionally, they should not be
redirected to the sign in form after confirmation
in this case. So I've changed
ConfirmationsController#after_confirmation_path_for
to send the user to the root path when signed in,
or the sign in form otherwise.
The :confirmed default message in devise.en.yml
used to say "You are now signed in." This is no
longer the default behavior in v3.1.0.
This commit renames that message to
:confirmed_and_signed_in and changes the :confirmed
message to be appropriate for the default post-
confirmation location (which is now the new session
page). The new :confirmed message reads:
"Your account was successfully confirmed. Please
sign in."
Devise::RegistrationsController#create set self.resource to the return value of build_resource--which is nil, because build_resource sets self.resource to an actual resource object. This caused attempting to save the resource (two lines down) to fail with "undefined method `save' on nil:NilClass."
