Allow null to be given to authenticable.

lib/devise/migrations.rb

@@ -19,10 +19,11 @@ module Devise
 
     # Creates email, encrypted_password and password_salt.
     #
-    def authenticable
-      string :email,              :limit => 100, :null => false
-      string :encrypted_password, :limit =>  40, :null => false
-      string :password_salt,      :limit =>  20, :null => false
+    def authenticable(options={})
+      null = options[:null] || false
+      string :email,              :limit => 100, :null => null
+      string :encrypted_password, :limit =>  40, :null => null
+      string :password_salt,      :limit =>  20, :null => null
     end
 
     # Creates confirmation_token, confirmed_at and confirmation_sent_at.

test/active_record_test.rb

@@ -93,4 +93,8 @@ class ActiveRecordTest < ActiveSupport::TestCase
   test 'set a default value for pepper' do
     assert_equal 'abcdef', Configurable.new.send(:pepper)
   end
+
+  test 'set null fields on migrations' do
+    Admin.create!
+  end
 end

test/rails_app/app/models/admin.rb

@@ -1,3 +1,3 @@
 class Admin < ActiveRecord::Base
-  devise :all, :except => [:recoverable, :confirmable, :rememberable]
+  devise :all, :except => [:recoverable, :confirmable, :rememberable, :validatable]
 end

test/test_helper.rb

@@ -16,7 +16,7 @@ ActiveRecord::Base.establish_connection(:adapter => "sqlite3", :database => ":me
 ActiveRecord::Schema.define(:version => 1) do
   [:users, :admins].each do |table|
     create_table table do |t|
-      t.authenticable
+      t.authenticable :null => table == :admins
 
       if table == :users
         t.confirmable