rails/rails — pull request #4818 by arunagw (2012-02-01 11:49:45+00:00)
Title: Build fix when running isolated test

fixed

```ruby
1) Error:
807test_should_return_string_as_json(MultibyteCharsTest):
808NoMethodError: undefined method `as_json' for "こにちわ":String
809 /home/vagrant/builds/rails/rails/activesupport/lib/active_support/multibyte/chars.rb:192:in `as_json'
810 /home/vagrant/builds/rails/rails/activesupport/test/multibyte_chars_test.rb:92:in `test_should_return_string_as_json'
811 /home/vagrant/builds/rails/rails/vendor/bundle/ruby/1.9.1/gems/mocha-0.10.3/lib/mocha/integration/mini_test/version_230_to_262.rb:28:in `run'
812 /home/vagrant/builds/rails/rails/activesupport/lib/active_support/testing/setup_and_teardown.rb:29:in `block in run'
813 /home/vagrant/builds/rails/rails/activesupport/lib/active_support/callbacks.rb:366:in `_run__36564177__setup__callbacks'
814 /home/vagrant/builds/rails/rails/activesupport/lib/active_support/callbacks.rb:368:in `__run_callbacks'
815 /home/vagrant/builds/rails/rails/activesupport/lib/active_support/callbacks.rb:80:in `run_callbacks'
816 /home/vagrant/builds/rails/rails/activesupport/lib/active_support/testing/setup_and_teardown.rb:28:in `run'

```