Use autoload to pre-load components (so they still work when rubygems are disabled)

lib/devise.rb

@@ -1,4 +1,8 @@
 module Devise
+  autoload :Schema, 'devise/schema'
+  autoload :Mapping, 'devise/mapping'
+  autoload :FailureApp, 'devise/failure_app'
+
   ALL = [:authenticatable, :confirmable, :recoverable, :rememberable,
          :timeoutable, :trackable, :validatable].freeze
 
@@ -144,6 +148,8 @@ end
 # Set the default_scope to nil, so it's overwritten when the first route is declared.
 Warden::Manager.default_scope = nil
 
+require 'devise/controllers'
+require 'devise/encryptors'
 require 'devise/strategies/base'
 require 'devise/serializers/base'
 require 'devise/rails'

lib/devise/controllers.rb

@@ -0,0 +1,7 @@
+module Devise
+  module Controllers
+    autoload :Filters, 'devise/controllers/filters' 
+    autoload :Helpers, 'devise/controllers/helpers' 
+    autoload :UrlHelpers, 'devise/controllers/url_helpers'     
+  end
+end

lib/devise/encryptors.rb

@@ -0,0 +1,9 @@
+module Devise
+  module Encryptors
+    autoload :AuthlogicSha512, 'devise/encryptors/authlogic_sha512' 
+    autoload :AuthlogicSha1, 'devise/encryptors/authlogic_sha1' 
+    autoload :RestfulAuthenticationSha1, 'devise/encryptors/restful_authentication_sha1' 
+    autoload :Sha512, 'devise/encryptors/sha512' 
+    autoload :Sha1, 'devise/encryptors/sha1' 
+  end
+end