50 files changed, 319 insertions, 84 deletions
diff --git a/railties/CHANGELOG.md b/railties/CHANGELOG.md
index 639dd70152..b80aa944e0 100644
--- a/railties/CHANGELOG.md
+++ b/railties/CHANGELOG.md
@@ -1,3 +1,24 @@
+*   Removed deprecated `Rails.application.railties.engines`.
+
+    *Arun Agrawal*
+
+*   Removed deprecated threadsafe! from Rails Config.
+
+    *Paul Nikitochkin*
+
+*   Remove deprecated `ActiveRecord::Generators::ActiveModel#update_attributes` in
+    favor of `ActiveRecord::Generators::ActiveModel#update`
+
+    *Vipul A M*
+
+*   Remove deprecated `config.whiny_nils` option
+
+    *Vipul A M*
+
+*   Rename `commands/plugin_new.rb` to `commands/plugin.rb` and fix references
+
+    *Richard Schneeman*
+
 *   Fix `rails plugin --help` command.
 
     *Richard Schneeman*
diff --git a/railties/lib/rails.rb b/railties/lib/rails.rb
index 3a3c11d8b3..ea82327365 100644
--- a/railties/lib/rails.rb
+++ b/railties/lib/rails.rb
@@ -10,7 +10,6 @@ require 'active_support/core_ext/array/extract_options'
 
 require 'rails/application'
 require 'rails/version'
-require 'rails/deprecation'
 
 require 'active_support/railtie'
 require 'action_dispatch/railtie'
diff --git a/railties/lib/rails/application.rb b/railties/lib/rails/application.rb
index b5c5a6191f..6fd01ee768 100644
--- a/railties/lib/rails/application.rb
+++ b/railties/lib/rails/application.rb
@@ -51,6 +51,29 @@ module Rails
   #   10) Run config.before_eager_load and eager_load! if eager_load is true
   #   11) Run config.after_initialize callbacks
   #
+  # == Multiple Applications
+  #
+  # If you decide to define multiple applications, then the first application
+  # that is initialized will be set to +Rails.application+, unless you override
+  # it with a different application.
+  #
+  # To create a new application, you can instantiate a new instance of a class
+  # that has already been created:
+  #
+  #   class Application < Rails::Application
+  #   end
+  #
+  #   first_application  = Application.new
+  #   second_application = Application.new(config: first_application.config)
+  #
+  # In the above example, the configuration from the first application was used
+  # to initialize the second application. You can also use the +initialize_copy+
+  # on one of the applications to create a copy of the application which shares
+  # the configuration.
+  #
+  # If you decide to define rake tasks, runners, or initializers in an
+  # application other than +Rails.application+, then you must run those
+  # these manually.
   class Application < Engine
     autoload :Bootstrap,              'rails/application/bootstrap'
     autoload :Configuration,          'rails/application/configuration'
@@ -61,12 +84,16 @@ module Rails
 
     class << self
       def inherited(base)
-        raise "You cannot have more than one Rails::Application" if Rails.application
         super
-        Rails.application = base.instance
-        Rails.application.add_lib_to_load_path!
-        ActiveSupport.run_load_hooks(:before_configuration, base.instance)
+        Rails.application ||= base.instance
       end
+
+      # Makes the +new+ method public.
+      #
+      # Note that Rails::Application inherits from Rails::Engine, which
+      # inherits from Rails::Railtie and the +new+ method on Rails::Railtie is
+      # private
+      public :new
     end
 
     attr_accessor :assets, :sandbox
@@ -75,14 +102,28 @@ module Rails
 
     delegate :default_url_options, :default_url_options=, to: :routes
 
-    def initialize
-      super
+    INITIAL_VARIABLES = [:config, :railties, :routes_reloader, :reloaders,
+                         :routes, :helpers, :app_env_config] # :nodoc:
+
+    def initialize(initial_variable_values = {}, &block)
+      super()
       @initialized      = false
       @reloaders        = []
       @routes_reloader  = nil
       @app_env_config   = nil
       @ordered_railties = nil
       @railties         = nil
+
+      add_lib_to_load_path!
+      ActiveSupport.run_load_hooks(:before_configuration, self)
+
+      initial_variable_values.each do |variable_name, value|
+        if INITIAL_VARIABLES.include?(variable_name)
+          instance_variable_set("@#{variable_name}", value)
+        end
+      end
+
+      instance_eval(&block) if block_given?
     end
 
     # Returns true if the application is initialized.
@@ -141,6 +182,30 @@ module Rails
       end
     end
 
+    # If you try to define a set of rake tasks on the instance, these will get
+    # passed up to the rake tasks defined on the application's class.
+    def rake_tasks(&block)
+      self.class.rake_tasks(&block)
+    end
+
+    # Sends the initializers to the +initializer+ method defined in the
+    # Rails::Initializable module. Each Rails::Application class has its own
+    # set of initializers, as defined by the Initializable module.
+    def initializer(name, opts={}, &block)
+      self.class.initializer(name, opts, &block)
+    end
+
+    # Sends any runner called in the instance of a new application up
+    # to the +runner+ method defined in Rails::Railtie.
+    def runner(&blk)
+      self.class.runner(&blk)
+    end
+
+    # Sends the +isolate_namespace+ method up to the class method.
+    def isolate_namespace(mod)
+      self.class.isolate_namespace(mod)
+    end
+
     ## Rails internal API
 
     # This method is called just after an application inherits from Rails::Application,
@@ -158,7 +223,9 @@ module Rails
     # you need to load files in lib/ during the application configuration as well.
     def add_lib_to_load_path! #:nodoc:
       path = File.join config.root, 'lib'
-      $LOAD_PATH.unshift(path) if File.exists?(path)
+      if File.exists?(path) && !$LOAD_PATH.include?(path)
+        $LOAD_PATH.unshift(path)
+      end
     end
 
     def require_environment! #:nodoc:
@@ -202,6 +269,10 @@ module Rails
       @config ||= Application::Configuration.new(find_root_with_flag("config.ru", Dir.pwd))
     end
 
+    def config=(configuration) #:nodoc:
+      @config = configuration
+    end
+
     def to_app #:nodoc:
       self
     end
diff --git a/railties/lib/rails/application/configuration.rb b/railties/lib/rails/application/configuration.rb
index 644893d9e1..7332444ab9 100644
--- a/railties/lib/rails/application/configuration.rb
+++ b/railties/lib/rails/application/configuration.rb
@@ -87,16 +87,6 @@ module Rails
         end
       end
 
-      def threadsafe!
-        message = "config.threadsafe! is deprecated. Rails applications " \
-                  "behave by default as thread safe in production as long as config.cache_classes and " \
-                  "config.eager_load are set to true"
-        ActiveSupport::Deprecation.warn message
-        @cache_classes = true
-        @eager_load = true
-        self
-      end
-
       # Loads and returns the configuration of the database.
       def database_configuration
         yaml = paths["config/database"].first
@@ -150,9 +140,6 @@ module Rails
         end
       end
 
-      def whiny_nils=(*)
-        ActiveSupport::Deprecation.warn "config.whiny_nils option is deprecated and no longer works"
-      end
     end
   end
 end
diff --git a/railties/lib/rails/cli.rb b/railties/lib/rails/cli.rb
index e5341ac436..20313a2608 100644
--- a/railties/lib/rails/cli.rb
+++ b/railties/lib/rails/cli.rb
@@ -10,7 +10,7 @@ Signal.trap("INT") { puts; exit(1) }
 
 if ARGV.first == 'plugin'
   ARGV.shift
-  require 'rails/commands/plugin_new'
+  require 'rails/commands/plugin'
 else
   require 'rails/commands/application'
 end
diff --git a/railties/lib/rails/commands.rb b/railties/lib/rails/commands.rb
index c2ce2b4d2a..3e8163490f 100644
--- a/railties/lib/rails/commands.rb
+++ b/railties/lib/rails/commands.rb
@@ -36,7 +36,7 @@ command = aliases[command] || command
 
 case command
 when 'plugin'
-  require "rails/commands/plugin_new"
+  require "rails/commands/plugin"
 when 'generate', 'destroy'
   require 'rails/generators'
 
diff --git a/railties/lib/rails/commands/plugin.rb b/railties/lib/rails/commands/plugin.rb
new file mode 100644
index 0000000000..837fe0ec10
--- /dev/null
+++ b/railties/lib/rails/commands/plugin.rb
@@ -0,0 +1,9 @@
+if ARGV.first != "new"
+  ARGV[0] = "--help"
+else
+  ARGV.shift
+end
+
+require 'rails/generators'
+require 'rails/generators/rails/plugin/plugin_generator'
+Rails::Generators::PluginGenerator.start
diff --git a/railties/lib/rails/commands/plugin_new.rb b/railties/lib/rails/commands/plugin_new.rb
deleted file mode 100644
index 4d7bf3c9f3..0000000000
--- a/railties/lib/rails/commands/plugin_new.rb
+++ /dev/null
@@ -1,9 +0,0 @@
-if ARGV.first != "new"
-  ARGV[0] = "--help"
-else
-  ARGV.shift
-end
-
-require 'rails/generators'
-require 'rails/generators/rails/plugin_new/plugin_new_generator'
-Rails::Generators::PluginNewGenerator.start
-\ No newline at end of file
diff --git a/railties/lib/rails/configuration.rb b/railties/lib/rails/configuration.rb
index 15d13d5f28..c694513960 100644
--- a/railties/lib/rails/configuration.rb
+++ b/railties/lib/rails/configuration.rb
@@ -1,4 +1,3 @@
-require 'active_support/deprecation'
 require 'active_support/ordered_options'
 require 'active_support/core_ext/object'
 require 'rails/paths'
diff --git a/railties/lib/rails/engine/railties.rb b/railties/lib/rails/engine/railties.rb
index 1081700cd0..595256f36a 100644
--- a/railties/lib/rails/engine/railties.rb
+++ b/railties/lib/rails/engine/railties.rb
@@ -9,10 +9,6 @@ module Rails
           ::Rails::Engine.subclasses.map(&:instance)
       end
 
-      def self.engines
-        @engines ||= ::Rails::Engine.subclasses.map(&:instance)
-      end
-
       def each(*args, &block)
         _all.each(*args, &block)
       end
@@ -25,5 +21,3 @@ module Rails
     end
   end
 end
-
-ActiveSupport::Deprecation.deprecate_methods(Rails::Engine::Railties, :engines)
diff --git a/railties/lib/rails/generators.rb b/railties/lib/rails/generators.rb
index 4b767ea0c6..6b34db3e3f 100644
--- a/railties/lib/rails/generators.rb
+++ b/railties/lib/rails/generators.rb
@@ -225,7 +225,7 @@ module Rails
       rails = groups.delete("rails")
       rails.map! { |n| n.sub(/^rails:/, '') }
       rails.delete("app")
-      rails.delete("plugin_new")
+      rails.delete("plugin")
       print_list("rails", rails)
 
       hidden_namespaces.each { |n| groups.delete(n.to_s) }
diff --git a/railties/lib/rails/generators/active_model.rb b/railties/lib/rails/generators/active_model.rb
index e5373704d7..6183944bb0 100644
--- a/railties/lib/rails/generators/active_model.rb
+++ b/railties/lib/rails/generators/active_model.rb
@@ -1,5 +1,3 @@
-require 'active_support/deprecation'
-
 module Rails
   module Generators
     # ActiveModel is a class to be implemented by each ORM to allow Rails to
@@ -65,12 +63,6 @@ module Rails
         "#{name}.update(#{params})"
       end
 
-      def update_attributes(*args) # :nodoc:
-        ActiveSupport::Deprecation.warn("Calling '@orm_instance.update_attributes' " \
-          "is deprecated, please use '@orm_instance.update' instead.")
-        update(*args)
-      end
-
       # POST create
       # PATCH/PUT update
       def errors
diff --git a/railties/lib/rails/generators/migration.rb b/railties/lib/rails/generators/migration.rb
index cd69a017dd..3566f96f5e 100644
--- a/railties/lib/rails/generators/migration.rb
+++ b/railties/lib/rails/generators/migration.rb
@@ -1,15 +1,14 @@
+require 'active_support/concern'
+
 module Rails
   module Generators
     # Holds common methods for migrations. It assumes that migrations has the
     # [0-9]*_name format and can be used by another frameworks (like Sequel)
     # just by implementing the next migration version method.
     module Migration
+      extend ActiveSupport::Concern
       attr_reader :migration_number, :migration_file_name, :migration_class_name
 
-      def self.included(base) #:nodoc:
-        base.extend ClassMethods
-      end
-
       module ClassMethods
         def migration_lookup_at(dirname) #:nodoc:
           Dir.glob("#{dirname}/[0-9]*_*.rb")
diff --git a/railties/lib/rails/generators/rails/plugin_new/USAGE b/railties/lib/rails/generators/rails/plugin/USAGE
index 9a7bf9f396..9a7bf9f396 100644
--- a/railties/lib/rails/generators/rails/plugin_new/USAGE
+++ b/railties/lib/rails/generators/rails/plugin/USAGE
diff --git a/railties/lib/rails/generators/rails/plugin_new/plugin_new_generator.rb b/railties/lib/rails/generators/rails/plugin/plugin_generator.rb
index 850c9d5c0d..13f5472ede 100644
--- a/railties/lib/rails/generators/rails/plugin_new/plugin_new_generator.rb
+++ b/railties/lib/rails/generators/rails/plugin/plugin_generator.rb
@@ -154,7 +154,7 @@ task default: :test
   end
 
   module Generators
-    class PluginNewGenerator < AppBase # :nodoc:
+    class PluginGenerator < AppBase # :nodoc:
       add_shared_options_for "plugin"
 
       alias_method :plugin_path, :app_path
diff --git a/railties/lib/rails/generators/rails/plugin_new/templates/%name%.gemspec b/railties/lib/rails/generators/rails/plugin/templates/%name%.gemspec
index 5fdf0e1554..5fdf0e1554 100644
--- a/railties/lib/rails/generators/rails/plugin_new/templates/%name%.gemspec
+++ b/railties/lib/rails/generators/rails/plugin/templates/%name%.gemspec
diff --git a/railties/lib/rails/generators/rails/plugin_new/templates/Gemfile b/railties/lib/rails/generators/rails/plugin/templates/Gemfile
index 3f2b78f2fd..3f2b78f2fd 100644
--- a/railties/lib/rails/generators/rails/plugin_new/templates/Gemfile
+++ b/railties/lib/rails/generators/rails/plugin/templates/Gemfile
diff --git a/railties/lib/rails/generators/rails/plugin_new/templates/MIT-LICENSE b/railties/lib/rails/generators/rails/plugin/templates/MIT-LICENSE
index d7a9109894..d7a9109894 100644
--- a/railties/lib/rails/generators/rails/plugin_new/templates/MIT-LICENSE
+++ b/railties/lib/rails/generators/rails/plugin/templates/MIT-LICENSE
diff --git a/railties/lib/rails/generators/rails/plugin_new/templates/README.rdoc b/railties/lib/rails/generators/rails/plugin/templates/README.rdoc
index 301d647731..301d647731 100644
--- a/railties/lib/rails/generators/rails/plugin_new/templates/README.rdoc
+++ b/railties/lib/rails/generators/rails/plugin/templates/README.rdoc
diff --git a/railties/lib/rails/generators/rails/plugin_new/templates/Rakefile b/railties/lib/rails/generators/rails/plugin/templates/Rakefile
index 0ba899176c..0ba899176c 100644
--- a/railties/lib/rails/generators/rails/plugin_new/templates/Rakefile
+++ b/railties/lib/rails/generators/rails/plugin/templates/Rakefile
diff --git a/railties/lib/rails/generators/rails/plugin_new/templates/app/controllers/%name%/application_controller.rb.tt b/railties/lib/rails/generators/rails/plugin/templates/app/controllers/%name%/application_controller.rb.tt
index 448ad7f989..448ad7f989 100644
--- a/railties/lib/rails/generators/rails/plugin_new/templates/app/controllers/%name%/application_controller.rb.tt
+++ b/railties/lib/rails/generators/rails/plugin/templates/app/controllers/%name%/application_controller.rb.tt
diff --git a/railties/lib/rails/generators/rails/plugin_new/templates/app/helpers/%name%/application_helper.rb.tt b/railties/lib/rails/generators/rails/plugin/templates/app/helpers/%name%/application_helper.rb.tt
index 40ae9f52c2..40ae9f52c2 100644
--- a/railties/lib/rails/generators/rails/plugin_new/templates/app/helpers/%name%/application_helper.rb.tt
+++ b/railties/lib/rails/generators/rails/plugin/templates/app/helpers/%name%/application_helper.rb.tt
diff --git a/railties/lib/rails/generators/rails/plugin_new/templates/app/mailers/.empty_directory b/railties/lib/rails/generators/rails/plugin/templates/app/mailers/.empty_directory
index e69de29bb2..e69de29bb2 100644
--- a/railties/lib/rails/generators/rails/plugin_new/templates/app/mailers/.empty_directory
+++ b/railties/lib/rails/generators/rails/plugin/templates/app/mailers/.empty_directory
diff --git a/railties/lib/rails/generators/rails/plugin_new/templates/app/models/.empty_directory b/railties/lib/rails/generators/rails/plugin/templates/app/models/.empty_directory
index e69de29bb2..e69de29bb2 100644
--- a/railties/lib/rails/generators/rails/plugin_new/templates/app/models/.empty_directory
+++ b/railties/lib/rails/generators/rails/plugin/templates/app/models/.empty_directory
diff --git a/railties/lib/rails/generators/rails/plugin_new/templates/app/views/layouts/%name%/application.html.erb.tt b/railties/lib/rails/generators/rails/plugin/templates/app/views/layouts/%name%/application.html.erb.tt
index 1d380420b4..1d380420b4 100644
--- a/railties/lib/rails/generators/rails/plugin_new/templates/app/views/layouts/%name%/application.html.erb.tt
+++ b/railties/lib/rails/generators/rails/plugin/templates/app/views/layouts/%name%/application.html.erb.tt
diff --git a/railties/lib/rails/generators/rails/plugin_new/templates/bin/rails.tt b/railties/lib/rails/generators/rails/plugin/templates/bin/rails.tt
index c8de9f3e0f..c8de9f3e0f 100644
--- a/railties/lib/rails/generators/rails/plugin_new/templates/bin/rails.tt
+++ b/railties/lib/rails/generators/rails/plugin/templates/bin/rails.tt
diff --git a/railties/lib/rails/generators/rails/plugin_new/templates/config/routes.rb b/railties/lib/rails/generators/rails/plugin/templates/config/routes.rb
index 8e158d5831..8e158d5831 100644
--- a/railties/lib/rails/generators/rails/plugin_new/templates/config/routes.rb
+++ b/railties/lib/rails/generators/rails/plugin/templates/config/routes.rb
diff --git a/railties/lib/rails/generators/rails/plugin_new/templates/gitignore b/railties/lib/rails/generators/rails/plugin/templates/gitignore
index 086d87818a..086d87818a 100644
--- a/railties/lib/rails/generators/rails/plugin_new/templates/gitignore
+++ b/railties/lib/rails/generators/rails/plugin/templates/gitignore
diff --git a/railties/lib/rails/generators/rails/plugin_new/templates/lib/%name%.rb b/railties/lib/rails/generators/rails/plugin/templates/lib/%name%.rb
index 40c074cced..40c074cced 100644
--- a/railties/lib/rails/generators/rails/plugin_new/templates/lib/%name%.rb
+++ b/railties/lib/rails/generators/rails/plugin/templates/lib/%name%.rb
diff --git a/railties/lib/rails/generators/rails/plugin_new/templates/lib/%name%/engine.rb b/railties/lib/rails/generators/rails/plugin/templates/lib/%name%/engine.rb
index 967668fe66..967668fe66 100644
--- a/railties/lib/rails/generators/rails/plugin_new/templates/lib/%name%/engine.rb
+++ b/railties/lib/rails/generators/rails/plugin/templates/lib/%name%/engine.rb
diff --git a/railties/lib/rails/generators/rails/plugin_new/templates/lib/%name%/version.rb b/railties/lib/rails/generators/rails/plugin/templates/lib/%name%/version.rb
index ef07ef2e19..ef07ef2e19 100644
--- a/railties/lib/rails/generators/rails/plugin_new/templates/lib/%name%/version.rb
+++ b/railties/lib/rails/generators/rails/plugin/templates/lib/%name%/version.rb
diff --git a/railties/lib/rails/generators/rails/plugin_new/templates/lib/tasks/%name%_tasks.rake b/railties/lib/rails/generators/rails/plugin/templates/lib/tasks/%name%_tasks.rake
index 7121f5ae23..7121f5ae23 100644
--- a/railties/lib/rails/generators/rails/plugin_new/templates/lib/tasks/%name%_tasks.rake
+++ b/railties/lib/rails/generators/rails/plugin/templates/lib/tasks/%name%_tasks.rake
diff --git a/railties/lib/rails/generators/rails/plugin_new/templates/rails/application.rb b/railties/lib/rails/generators/rails/plugin/templates/rails/application.rb
index 310c975262..310c975262 100644
--- a/railties/lib/rails/generators/rails/plugin_new/templates/rails/application.rb
+++ b/railties/lib/rails/generators/rails/plugin/templates/rails/application.rb
diff --git a/railties/lib/rails/generators/rails/plugin_new/templates/rails/boot.rb b/railties/lib/rails/generators/rails/plugin/templates/rails/boot.rb
index ef360470a3..ef360470a3 100644
--- a/railties/lib/rails/generators/rails/plugin_new/templates/rails/boot.rb
+++ b/railties/lib/rails/generators/rails/plugin/templates/rails/boot.rb
diff --git a/railties/lib/rails/generators/rails/plugin_new/templates/rails/javascripts.js b/railties/lib/rails/generators/rails/plugin/templates/rails/javascripts.js
index 5bc2e1c8b5..5bc2e1c8b5 100644
--- a/railties/lib/rails/generators/rails/plugin_new/templates/rails/javascripts.js
+++ b/railties/lib/rails/generators/rails/plugin/templates/rails/javascripts.js
diff --git a/railties/lib/rails/generators/rails/plugin_new/templates/rails/routes.rb b/railties/lib/rails/generators/rails/plugin/templates/rails/routes.rb
index 730ee31c3d..730ee31c3d 100644
--- a/railties/lib/rails/generators/rails/plugin_new/templates/rails/routes.rb
+++ b/railties/lib/rails/generators/rails/plugin/templates/rails/routes.rb
diff --git a/railties/lib/rails/generators/rails/plugin_new/templates/rails/stylesheets.css b/railties/lib/rails/generators/rails/plugin/templates/rails/stylesheets.css
index 3192ec897b..3192ec897b 100644
--- a/railties/lib/rails/generators/rails/plugin_new/templates/rails/stylesheets.css
+++ b/railties/lib/rails/generators/rails/plugin/templates/rails/stylesheets.css
diff --git a/railties/lib/rails/generators/rails/plugin_new/templates/test/%name%_test.rb b/railties/lib/rails/generators/rails/plugin/templates/test/%name%_test.rb
index 0a8bbd4aaf..0a8bbd4aaf 100644
--- a/railties/lib/rails/generators/rails/plugin_new/templates/test/%name%_test.rb
+++ b/railties/lib/rails/generators/rails/plugin/templates/test/%name%_test.rb
diff --git a/railties/lib/rails/generators/rails/plugin_new/templates/test/integration/navigation_test.rb b/railties/lib/rails/generators/rails/plugin/templates/test/integration/navigation_test.rb
index 824caecb24..824caecb24 100644
--- a/railties/lib/rails/generators/rails/plugin_new/templates/test/integration/navigation_test.rb
+++ b/railties/lib/rails/generators/rails/plugin/templates/test/integration/navigation_test.rb
diff --git a/railties/lib/rails/generators/rails/plugin_new/templates/test/test_helper.rb b/railties/lib/rails/generators/rails/plugin/templates/test/test_helper.rb
index 1e26a313cd..1e26a313cd 100644
--- a/railties/lib/rails/generators/rails/plugin_new/templates/test/test_helper.rb
+++ b/railties/lib/rails/generators/rails/plugin/templates/test/test_helper.rb
diff --git a/railties/lib/rails/info.rb b/railties/lib/rails/info.rb
index f06ce659c5..5b69605b51 100644
--- a/railties/lib/rails/info.rb
+++ b/railties/lib/rails/info.rb
@@ -61,8 +61,10 @@ module Rails
       end
     end
 
-    # The Ruby version and platform, e.g. "1.8.2 (powerpc-darwin8.2.0)".
-    property 'Ruby version', "#{RUBY_VERSION} (#{RUBY_PLATFORM})"
+    # The Ruby version and platform, e.g. "2.0.0-p247 (x86_64-darwin12.4.0)".
+    property 'Ruby version' do
+      "#{RUBY_VERSION}-p#{RUBY_PATCHLEVEL} (#{RUBY_PLATFORM})"
+    end
 
     # The RubyGems version, if it's installed.
     property 'RubyGems version' do
diff --git a/railties/lib/rails/tasks/engine.rake b/railties/lib/rails/tasks/engine.rake
index 70370be3f5..16ad1bfc84 100644
--- a/railties/lib/rails/tasks/engine.rake
+++ b/railties/lib/rails/tasks/engine.rake
@@ -26,7 +26,7 @@ namespace :db do
   desc "Display status of migrations"
   app_task "migrate:status"
 
-  desc 'Create the database from config/database.yml for the current Rails.env (use db:create:all to create all dbs in the config)'
+  desc 'Create the database from config/database.yml for the current Rails.env (use db:create:all to create all databases in the config)'
   app_task "create"
   app_task "create:all"
 
diff --git a/railties/lib/rails/test_unit/sub_test_task.rb b/railties/lib/rails/test_unit/sub_test_task.rb
index a463380e2d..d9bffba4d7 100644
--- a/railties/lib/rails/test_unit/sub_test_task.rb
+++ b/railties/lib/rails/test_unit/sub_test_task.rb
@@ -2,13 +2,53 @@ require 'rake/testtask'
 
 module Rails
   class TestTask < Rake::TestTask # :nodoc: all
+    # A utility class which is used primarily in "rails/test_unit/testing.rake"
+    # to help define rake tasks corresponding to <tt>rake test</tt>.
+    #
+    # This class takes a TestInfo class and defines the appropriate rake task
+    # based on the information, then invokes it.
+    class TestCreator
+      def initialize(info)
+        @info = info
+      end
+
+      def invoke_rake_task
+        if @info.files.any?
+          create_and_run_single_test
+          reset_application_tasks
+        else
+          Rake::Task[ENV['TEST'] ? 'test:single' : 'test:run'].invoke
+        end
+      end
+
+      private
+
+        def create_and_run_single_test
+          Rails::TestTask.new('test:single') { |t|
+            t.test_files = @info.files
+          }
+          ENV['TESTOPTS'] ||= @info.opts
+          Rake::Task['test:single'].invoke
+        end
+
+        def reset_application_tasks
+          Rake.application.top_level_tasks.replace @info.tasks
+        end
+    end
+
+    # This is a utility class used by the <tt>TestTask::TestCreator</tt> class.
+    # This class takes a set of test tasks and checks to see if they correspond
+    # to test files (or can be transformed into test files). Calling <tt>files</tt>
+    # provides the set of test files and is used when initializing tests after
+    # a call to <tt>rake test</tt>.
     class TestInfo
       def initialize(tasks)
         @tasks = tasks
+        @files = nil
       end
 
       def files
-        @tasks.map { |task|
+        @files ||= @tasks.map { |task|
           [task, translate(task)].find { |file| test_file?(file) }
         }.compact
       end
@@ -53,8 +93,9 @@ module Rails
       end
     end
 
-    def self.test_info(tasks)
-      TestInfo.new tasks
+    def self.test_creator(tasks)
+      info = TestInfo.new(tasks)
+      TestCreator.new(info)
     end
 
     def initialize(name = :test)
diff --git a/railties/lib/rails/test_unit/testing.rake b/railties/lib/rails/test_unit/testing.rake
index 2e23999a91..3aa33d1bba 100644
--- a/railties/lib/rails/test_unit/testing.rake
+++ b/railties/lib/rails/test_unit/testing.rake
@@ -1,24 +1,12 @@
 require 'rbconfig'
 require 'rake/testtask'
 require 'rails/test_unit/sub_test_task'
-require 'active_support/deprecation'
 
 task default: :test
 
 desc 'Runs test:units, test:functionals, test:integration together'
 task :test do
-  info = Rails::TestTask.test_info Rake.application.top_level_tasks
-  if info.files.any?
-    Rails::TestTask.new('test:single') { |t|
-      t.test_files = info.files
-    }
-    ENV['TESTOPTS'] ||= info.opts
-    Rake.application.top_level_tasks.replace info.tasks
-
-    Rake::Task['test:single'].invoke
-  else
-    Rake::Task[ENV['TEST'] ? 'test:single' : 'test:run'].invoke
-  end
+  Rails::TestTask.test_creator(Rake.application.top_level_tasks).invoke_rake_task
 end
 
 namespace :test do
diff --git a/railties/test/application/initializers/frameworks_test.rb b/railties/test/application/initializers/frameworks_test.rb
index 33659db927..83104acf3c 100644
--- a/railties/test/application/initializers/frameworks_test.rb
+++ b/railties/test/application/initializers/frameworks_test.rb
@@ -182,7 +182,7 @@ module ApplicationTests
       end
       require "#{app_path}/config/environment"
       ActiveRecord::Base.connection.drop_table("posts") # force drop posts table for test.
-      assert ActiveRecord::Base.connection.schema_cache.tables["posts"]
+      assert ActiveRecord::Base.connection.schema_cache.tables("posts")
     end
 
     test "expire schema cache dump" do
@@ -192,7 +192,7 @@ module ApplicationTests
       end
       silence_warnings {
         require "#{app_path}/config/environment"
-        assert !ActiveRecord::Base.connection.schema_cache.tables["posts"]
+        assert !ActiveRecord::Base.connection.schema_cache.tables("posts")
       }
     end
 
diff --git a/railties/test/application/loading_test.rb b/railties/test/application/loading_test.rb
index f05eade81f..4f30f30f95 100644
--- a/railties/test/application/loading_test.rb
+++ b/railties/test/application/loading_test.rb
@@ -36,7 +36,7 @@ class LoadingTest < ActiveSupport::TestCase
   test "models without table do not panic on scope definitions when loaded" do
     app_file "app/models/user.rb", <<-MODEL
       class User < ActiveRecord::Base
-        default_scope where(published: true)
+        default_scope { where(published: true) }
       end
     MODEL
 
diff --git a/railties/test/application/multiple_applications_test.rb b/railties/test/application/multiple_applications_test.rb
new file mode 100644
index 0000000000..03c343c475
--- /dev/null
+++ b/railties/test/application/multiple_applications_test.rb
@@ -0,0 +1,148 @@
+require 'isolation/abstract_unit'
+
+module ApplicationTests
+  class MultipleApplicationsTest < ActiveSupport::TestCase
+    include ActiveSupport::Testing::Isolation
+
+    def setup
+      build_app(initializers: true)
+      boot_rails
+      require "#{rails_root}/config/environment"
+    end
+
+    def teardown
+      teardown_app
+    end
+
+    def test_cloning_an_application_makes_a_shallow_copy_of_config
+      clone = Rails.application.clone
+
+      assert_equal Rails.application.config, clone.config, "The cloned application should get a copy of the config"
+      assert_equal Rails.application.config.secret_key_base, clone.config.secret_key_base, "The base secret key on the config should be the same"
+    end
+
+    def test_initialization_of_multiple_copies_of_same_application
+      application1 = AppTemplate::Application.new
+      application2 = AppTemplate::Application.new
+
+      assert_not_equal Rails.application.object_id, application1.object_id, "New applications should not be the same as the original application"
+      assert_not_equal Rails.application.object_id, application2.object_id, "New applications should not be the same as the original application"
+    end
+
+    def test_initialization_of_application_with_previous_config
+      application1 = AppTemplate::Application.new(config: Rails.application.config)
+      application2 = AppTemplate::Application.new
+
+      assert_equal Rails.application.config, application1.config, "Creating a new application while setting an initial config should result in the same config"
+      assert_not_equal Rails.application.config, application2.config, "New applications without setting an initial config should not have the same config"
+    end
+
+    def test_initialization_of_application_with_previous_railties
+      application1 = AppTemplate::Application.new(railties: Rails.application.railties)
+      application2 = AppTemplate::Application.new
+
+      assert_equal Rails.application.railties, application1.railties
+      assert_not_equal Rails.application.railties, application2.railties
+    end
+
+    def test_initialize_new_application_with_all_previous_initialization_variables
+      application1 = AppTemplate::Application.new(
+        config:           Rails.application.config,
+        railties:         Rails.application.railties,
+        routes_reloader:  Rails.application.routes_reloader,
+        reloaders:        Rails.application.reloaders,
+        routes:           Rails.application.routes,
+        helpers:          Rails.application.helpers,
+        app_env_config:   Rails.application.env_config
+      )
+
+      assert_equal Rails.application.config, application1.config
+      assert_equal Rails.application.railties, application1.railties
+      assert_equal Rails.application.routes_reloader, application1.routes_reloader
+      assert_equal Rails.application.reloaders, application1.reloaders
+      assert_equal Rails.application.routes, application1.routes
+      assert_equal Rails.application.helpers, application1.helpers
+      assert_equal Rails.application.env_config, application1.env_config
+    end
+
+    def test_rake_tasks_defined_on_different_applications_go_to_the_same_class
+      $run_count = 0
+
+      application1 = AppTemplate::Application.new
+      application1.rake_tasks do
+        $run_count += 1
+      end
+
+      application2 = AppTemplate::Application.new
+      application2.rake_tasks do
+        $run_count += 1
+      end
+
+      require "#{app_path}/config/environment"
+
+      assert_equal 0, $run_count, "The count should stay at zero without any calls to the rake tasks"
+      require 'rake'
+      require 'rake/testtask'
+      require 'rdoc/task'
+      Rails.application.load_tasks
+      assert_equal 2, $run_count, "Calling a rake task should result in two increments to the count"
+    end
+
+    def test_multiple_applications_can_be_initialized
+      assert_nothing_raised { AppTemplate::Application.new }
+    end
+
+    def test_initializers_run_on_different_applications_go_to_the_same_class
+      application1 = AppTemplate::Application.new
+      $run_count = 0
+
+      AppTemplate::Application.initializer :init0 do
+        $run_count += 1
+      end
+
+      application1.initializer :init1 do
+        $run_count += 1
+      end
+
+      AppTemplate::Application.new.initializer :init2 do
+        $run_count += 1
+      end
+
+      assert_equal 0, $run_count, "Without loading the initializers, the count should be 0"
+
+      # Set config.eager_load to false so that a eager_load warning doesn't pop up
+      AppTemplate::Application.new { config.eager_load = false }.initialize!
+
+      assert_equal 3, $run_count, "There should have been three initializers that incremented the count"
+    end
+
+    def test_runners_run_on_different_applications_go_to_the_same_class
+      $run_count = 0
+      AppTemplate::Application.runner { $run_count += 1 }
+      AppTemplate::Application.new.runner { $run_count += 1 }
+
+      assert_equal 0, $run_count, "Without loading the runners, the count should be 0"
+      Rails.application.load_runner
+      assert_equal 2, $run_count, "There should have been two runners that increment the count"
+    end
+
+    def test_isolate_namespace_on_an_application
+      assert_nil Rails.application.railtie_namespace, "Before isolating namespace, the railtie namespace should be nil"
+      Rails.application.isolate_namespace(AppTemplate)
+      assert_equal Rails.application.railtie_namespace, AppTemplate, "After isolating namespace, we should have a namespace"
+    end
+
+    def test_inserting_configuration_into_application
+      app = AppTemplate::Application.new(config: Rails.application.config)
+      new_config = Rails::Application::Configuration.new("root_of_application")
+      new_config.secret_key_base = "some_secret_key_dude"
+      app.config.secret_key_base = "a_different_secret_key"
+
+      assert_equal "a_different_secret_key", app.config.secret_key_base, "The configuration's secret key should be set."
+      app.config = new_config
+      assert_equal "some_secret_key_dude", app.config.secret_key_base, "The configuration's secret key should have changed."
+      assert_equal "root_of_application", app.config.root, "The root should have changed to the new config's root."
+      assert_equal new_config, app.config, "The application's config should have changed to the new config."
+    end
+  end
+end
diff --git a/railties/test/generators/plugin_new_generator_test.rb b/railties/test/generators/plugin_generator_test.rb
index 32c7612a8f..068eb66bc6 100644
--- a/railties/test/generators/plugin_new_generator_test.rb
+++ b/railties/test/generators/plugin_generator_test.rb
@@ -1,5 +1,5 @@
 require 'generators/generators_test_helper'
-require 'rails/generators/rails/plugin_new/plugin_new_generator'
+require 'rails/generators/rails/plugin/plugin_generator'
 require 'generators/shared_generator_tests'
 
 DEFAULT_PLUGIN_FILES = %w(
@@ -18,7 +18,7 @@ DEFAULT_PLUGIN_FILES = %w(
   test/dummy
 )
 
-class PluginNewGeneratorTest < Rails::Generators::TestCase
+class PluginGeneratorTest < Rails::Generators::TestCase
   include GeneratorsTestHelper
   destination File.join(Rails.root, "tmp/bukkits")
   arguments [destination_root]
diff --git a/railties/test/generators_test.rb b/railties/test/generators_test.rb
index 361784f509..5130b285a9 100644
--- a/railties/test/generators_test.rb
+++ b/railties/test/generators_test.rb
@@ -106,7 +106,7 @@ class GeneratorsTest < Rails::Generators::TestCase
   def test_rails_generators_help_does_not_include_app_nor_plugin_new
     output = capture(:stdout){ Rails::Generators.help }
     assert_no_match(/app/, output)
-    assert_no_match(/plugin_new/, output)
+    assert_no_match(/[^:]plugin/, output)
   end
 
   def test_rails_generators_with_others_information
diff --git a/railties/test/railties/engine_test.rb b/railties/test/railties/engine_test.rb
index 50253fe2bc..d095535abd 100644
--- a/railties/test/railties/engine_test.rb
+++ b/railties/test/railties/engine_test.rb
@@ -1236,12 +1236,6 @@ YAML
       assert_equal '/foo/bukkits/bukkit', last_response.body
     end
 
-    test "engines method is properly deprecated" do
-      boot_rails
-
-      assert_deprecated { app.railties.engines }
-    end
-
   private
     def app
       Rails.application