3 files changed, 38 insertions, 18 deletions

diff --git a/railties/lib/rails/command/actions.rb b/railties/lib/rails/command/actions.rb
index 31b656ec31..8fda1c87c6 100644
--- a/railties/lib/rails/command/actions.rb
+++ b/railties/lib/rails/command/actions.rb
@@ -8,11 +8,16 @@ module Rails
         Dir.chdir(File.expand_path("../../", APP_PATH)) unless File.exist?(File.expand_path("config.ru"))
       end
 
-      if defined?(ENGINE_PATH)
-        def require_application_and_environment!
-          require ENGINE_PATH
+      def require_application_and_environment!
+        require ENGINE_PATH if defined?(ENGINE_PATH)
+
+        if defined?(APP_PATH)
+          require APP_PATH
+          Rails.application.require_environment!
         end
+      end
 
+      if defined?(ENGINE_PATH)
         def load_tasks
           Rake.application.init("rails")
           Rake.application.load_rakefile
@@ -24,11 +29,6 @@ module Rails
           engine.load_generators
         end
       else
-        def require_application_and_environment!
-          require APP_PATH
-          Rails.application.require_environment!
-        end
-
         def load_tasks
           Rails.application.load_tasks
         end
diff --git a/railties/lib/rails/command/base.rb b/railties/lib/rails/command/base.rb
index 1efcd69e63..4f074df473 100644
--- a/railties/lib/rails/command/base.rb
+++ b/railties/lib/rails/command/base.rb
@@ -22,7 +22,7 @@ module Rails
 
         # Tries to get the description from a USAGE file one folder above the command
         # root.
-        def desc(usage = nil, description = nil)
+        def desc(usage = nil, description = nil, options = {})
           if usage
             super
           else
@@ -56,13 +56,15 @@ module Rails
         end
 
         def perform(command, args, config) # :nodoc:
-          command = nil if Thor::HELP_MAPPINGS.include?(args.first)
+          if Rails::Command::HELP_MAPPINGS.include?(args.first)
+            command, args = "help", []
+          end
 
           dispatch(command, args.dup, nil, config)
         end
 
         def printing_commands
-          namespace.sub(/^rails:/, "")
+          namespaced_commands
         end
 
         def executable
@@ -111,7 +113,7 @@ module Rails
         # For a `Rails::Command::TestCommand` placed in `rails/command/test_command.rb`
         # would return `rails/test`.
         def default_command_root
-          path = File.expand_path(File.join("../commands", command_name), __dir__)
+          path = File.expand_path(File.join("../commands", command_root_namespace), __dir__)
           path if File.exist?(path)
         end
 
@@ -129,6 +131,24 @@ module Rails
               super
             end
           end
+
+          def command_root_namespace
+            (namespace.split(":") - %w( rails )).first
+          end
+
+          def namespaced_commands
+            commands.keys.map do |key|
+              key == command_root_namespace ? key : "#{command_root_namespace}:#{key}"
+            end
+          end
+      end
+
+      def help
+        if command_name = self.class.command_name
+          self.class.command_help(shell, command_name)
+        else
+          super
+        end
       end
     end
   end
diff --git a/railties/lib/rails/command/behavior.rb b/railties/lib/rails/command/behavior.rb
index 2e8517070c..4a92f72f16 100644
--- a/railties/lib/rails/command/behavior.rb
+++ b/railties/lib/rails/command/behavior.rb
@@ -16,13 +16,13 @@ module Rails
           @subclasses ||= []
         end
 
-        protected
+        private
 
           # This code is based directly on the Text gem implementation.
           # Copyright (c) 2006-2013 Paul Battley, Michael Neumann, Tim Fletcher.
           #
           # Returns a value representing the "cost" of transforming str1 into str2.
-          def levenshtein_distance(str1, str2)
+          def levenshtein_distance(str1, str2) # :doc:
             s = str1
             t = str2
             n = s.length
@@ -58,7 +58,7 @@ module Rails
           end
 
           # Prints a list of generators.
-          def print_list(base, namespaces) #:nodoc:
+          def print_list(base, namespaces)
             return if namespaces.empty?
             puts "#{base.camelize}:"
 
@@ -71,7 +71,7 @@ module Rails
 
           # Receives namespaces in an array and tries to find matching generators
           # in the load path.
-          def lookup(namespaces) #:nodoc:
+          def lookup(namespaces)
             paths = namespaces_to_paths(namespaces)
 
             paths.each do |raw_path|
@@ -91,7 +91,7 @@ module Rails
           end
 
           # This will try to load any command in the load path to show in help.
-          def lookup! #:nodoc:
+          def lookup!
             $LOAD_PATH.each do |base|
               Dir[File.join(base, *file_lookup_paths)].each do |path|
                 begin
@@ -107,7 +107,7 @@ module Rails
           # Convert namespaces to paths by replacing ":" for "/" and adding
           # an extra lookup. For example, "rails:model" should be searched
           # in both: "rails/model/model_generator" and "rails/model_generator".
-          def namespaces_to_paths(namespaces) #:nodoc:
+          def namespaces_to_paths(namespaces)
             paths = []
             namespaces.each do |namespace|
               pieces = namespace.split(":")