fix test_helper for mountable plugin

railties/lib/rails/generators/rails/plugin/templates/test/test_helper.rb

@@ -4,6 +4,9 @@
 require File.expand_path("../../<%= options[:dummy_path] -%>/config/environment.rb",  __FILE__)
 <% unless options[:skip_active_record] -%>
 ActiveRecord::Migrator.migrations_paths = [File.expand_path("../../<%= options[:dummy_path] -%>/db/migrate", __FILE__)]
+<% if options[:mountable] -%>
+ActiveRecord::Migrator.migrations_paths << File.expand_path('../../db/migrate', __FILE__)
+<% end -%>
 <% end -%>
 require "rails/test_help"
 

railties/test/generators/plugin_generator_test.rb

@@ -245,6 +245,10 @@ def test_create_mountable_application_with_mountable_option
       assert_match(/stylesheet_link_tag\s+['"]bukkits\/application['"]/, contents)
       assert_match(/javascript_include_tag\s+['"]bukkits\/application['"]/, contents)
     end
+    assert_file "test/test_helper.rb" do |content|
+      assert_match(/ActiveRecord::Migrator\.migrations_paths.+\.\.\/test\/dummy\/db\/migrate/, content)
+      assert_match(/ActiveRecord::Migrator\.migrations_paths.+<<.+\.\.\/db\/migrate/, content)
+    end
   end
 
   def test_creating_gemspec