use a delegate for `username` to be more future friendly

app/controllers/confirmations_controller.rb

@@ -15,8 +15,7 @@ class ConfirmationsController < Devise::ConfirmationsController
     if signed_in?(:user)
       after_sign_in(resource)
     else
-      username = (resource_name == :email ? resource.user.username : resource.username)
-      Gitlab::AppLogger.info("Email Confirmed: username=#{username} email=#{resource.email} ip=#{request.remote_ip}")
+      Gitlab::AppLogger.info("Email Confirmed: username=#{resource.username} email=#{resource.email} ip=#{request.remote_ip}")
       flash[:notice] += " Please sign in."
       new_session_path(:user)
     end

app/models/email.rb

@@ -14,6 +14,8 @@ class Email < ActiveRecord::Base
   devise :confirmable
   self.reconfirmable = false  # currently email can't be changed, no need to reconfirm
 
+  delegate :username, to: :user
+
   def email=(value)
     write_attribute(:email, value.downcase.strip)
   end

spec/models/email_spec.rb

@@ -40,4 +40,12 @@ describe Email do
       expect(user.emails.confirmed.count).to eq 1
     end
   end
+  
+  describe 'delegation' do
+    let(:user) { create(:user) }
+    
+    it 'delegates to :user' do
+      expect(build(:email, user: user).username).to eq user.username
+    end
+  end
 end