CAS Auth Fixes

Signed-off-by: Thomas Citharel <tcit@tcit.fr>

lib/web/controllers/auth_controller.ex

@@ -4,6 +4,7 @@ defmodule Mobilizon.Web.AuthController do
   alias Mobilizon.Service.Auth.Authenticator
   alias Mobilizon.Users
   alias Mobilizon.Users.User
+  import Mobilizon.Service.Guards, only: [is_valid_string: 1]
   require Logger
   plug(:put_layout, false)
 
@@ -106,7 +107,11 @@ defmodule Mobilizon.Web.AuthController do
   defp email_from_ueberauth(%Ueberauth.Auth{
          extra: %Ueberauth.Auth.Extra{raw_info: %{user: %{"email" => email}}}
        })
-       when not is_nil(email) and email != "",
+       when is_valid_string(email),
+       do: email
+
+  defp email_from_ueberauth(%Ueberauth.Auth{info: %Ueberauth.Auth.Info{email: email}})
+       when is_valid_string(email),
        do: email
 
   defp email_from_ueberauth(_), do: nil