3 files changed, 59 insertions, 7 deletions
diff --git a/railties/lib/rails/application.rb b/railties/lib/rails/application.rb
index d1e88cfafd..e45bfaf6fc 100644
--- a/railties/lib/rails/application.rb
+++ b/railties/lib/rails/application.rb
@@ -1,6 +1,7 @@
 require 'fileutils'
 require 'active_support/core_ext/object/blank'
 require 'active_support/key_generator'
+require 'active_support/message_verifier'
 require 'rails/engine'
 
 module Rails
@@ -107,12 +108,13 @@ module Rails
 
     def initialize(initial_variable_values = {}, &block)
       super()
-      @initialized      = false
-      @reloaders        = []
-      @routes_reloader  = nil
-      @app_env_config   = nil
-      @ordered_railties = nil
-      @railties         = nil
+      @initialized       = false
+      @reloaders         = []
+      @routes_reloader   = nil
+      @app_env_config    = nil
+      @ordered_railties  = nil
+      @railties          = nil
+      @message_verifiers = {}
 
       add_lib_to_load_path!
       ActiveSupport.run_load_hooks(:before_configuration, self)
@@ -158,6 +160,31 @@ module Rails
       end
     end
 
+    # Returns a message verifier object.
+    #
+    # This verifier can be used to generate and verify signed messages in the application.
+    #
+    # It is recommended not to use the same verifier for different things, so you can get different
+    # verifiers passing the +verifier_name+ argument.
+    #
+    # ==== Parameters
+    #
+    # * +salt+ - the salt that will be used to generate the secret key of the verifier.
+    #
+    # ==== Examples
+    #
+    #     message = Rails.application.message_verifier('salt').generate('my sensible data')
+    #     Rails.application.message_verifier('salt').verify(message)
+    #     # => 'my sensible data'
+    #
+    # See the +ActiveSupport::MessageVerifier+ documentation for more information.
+    def message_verifier(salt)
+      @message_verifiers[salt] ||= begin
+        secret = key_generator.generate_key(salt)
+        ActiveSupport::MessageVerifier.new(secret)
+      end
+    end
+
     # Stores some of the Rails initial environment parameters which
     # will be used by middlewares and engines to configure themselves.
     def env_config
diff --git a/railties/lib/rails/generators/app_base.rb b/railties/lib/rails/generators/app_base.rb
index 2022b4ed3d..5d4682f6e3 100644
--- a/railties/lib/rails/generators/app_base.rb
+++ b/railties/lib/rails/generators/app_base.rb
@@ -47,6 +47,9 @@ module Rails
         class_option :skip_sprockets,     type: :boolean, aliases: '-S', default: false,
                                           desc: 'Skip Sprockets files'
 
+        class_option :skip_spring,        type: :boolean, default: false,
+                                          desc: "Don't install Spring application preloader"
+
         class_option :database,           type: :string, aliases: '-d', default: 'sqlite3',
                                           desc: "Preconfigure for selected database (options: #{DATABASES.join('/')})"
 
@@ -109,6 +112,7 @@ module Rails
           jbuilder_gemfile_entry,
           sdoc_gemfile_entry,
           platform_dependent_gemfile_entry,
+          spring_gemfile_entry,
           @extra_entries].flatten.find_all(&@gem_filter)
       end
 
@@ -365,6 +369,12 @@ module Rails
         end
       end
 
+      def spring_gemfile_entry
+        return [] unless spring_install?
+        comment = 'Spring speeds up development by keeping your application running in the background. Read more: https://github.com/jonleighton/spring'
+        GemfileEntry.new('spring', nil, comment, group: :development)
+      end
+
       def bundle_command(command)
         say_status :run, "bundle #{command}"
 
@@ -388,8 +398,22 @@ module Rails
         end
       end
 
+      def bundle_install?
+        !(options[:skip_gemfile] || options[:skip_bundle] || options[:pretend])
+      end
+
+      def spring_install?
+        !options[:skip_spring] && Process.respond_to?(:fork)
+      end
+
       def run_bundle
-        bundle_command('install') unless options[:skip_gemfile] || options[:skip_bundle] || options[:pretend]
+        bundle_command('install') if bundle_install?
+      end
+
+      def generate_spring_binstubs
+        if bundle_install? && spring_install?
+          bundle_command("exec spring binstub --all")
+        end
       end
 
       def empty_directory_with_keep_file(destination, config = {})
diff --git a/railties/lib/rails/generators/rails/app/app_generator.rb b/railties/lib/rails/generators/rails/app/app_generator.rb
index a2023886cd..87556bd609 100644
--- a/railties/lib/rails/generators/rails/app/app_generator.rb
+++ b/railties/lib/rails/generators/rails/app/app_generator.rb
@@ -237,6 +237,7 @@ module Rails
 
       public_task :run_bundle
       public_task :replay_template
+      public_task :generate_spring_binstubs
 
     protected