Ensure application rake tasks and generators are loaded after the ones specified in railties/engines/rails. [#4471 state:resolved]

railties/lib/rails/application.rb

@@ -112,15 +112,15 @@ def initialize!
 
     def load_tasks
       initialize_tasks
-      super
       railties.all { |r| r.load_tasks }
+      super
       self
     end
 
     def load_generators
       initialize_generators
-      super
       railties.all { |r| r.load_generators }
+      super
       self
     end
 

railties/lib/rails/tasks/documentation.rake

@@ -1,3 +1,5 @@
+require 'rake/rdoctask'
+
 namespace :doc do
   def gem_path(gem_name)
     path = $LOAD_PATH.grep(/#{gem_name}[\w.-]*\/lib$/).first

railties/lib/rails/test_unit/testing.rake

@@ -1,3 +1,5 @@
+require 'rake/testtask'
+
 TEST_CHANGES_SINCE = Time.now - 600
 
 # Look up tests for recently modified sources.

railties/test/application/rake_test.rb

@@ -0,0 +1,23 @@
+require "isolation/abstract_unit"
+
+module ApplicationTests
+  class RakeTest < Test::Unit::TestCase
+    include ActiveSupport::Testing::Isolation
+
+    def setup
+      build_app
+      boot_rails
+      FileUtils.rm_rf("#{app_path}/config/environments")
+    end
+    
+    def test_gems_tasks_are_loaded_first_than_application_ones
+      app_file "lib/tasks/app.rake", <<-RUBY
+        $task_loaded = Rake::Task.task_defined?("db:create:all")
+      RUBY
+      
+      require "#{app_path}/config/environment"
+      ::Rails.application.load_tasks
+      assert $task_loaded
+    end
+  end
+end