rails/rails — pull request #5237 by rohit (2012-03-02 02:18:24+00:00)
Title: Silence Active Support warning about @dirty not being initialized

Running the Active Support tests gives one warning from within Active Support:

```
/home/rohit/projects/rails/activesupport/lib/active_support/core_ext/string/output_safety.rb:130: warning: instance variable @dirty not initialized
```

On checking the code it seems like the intention is to set :@dirty to nil. On doing that the tests pass. If I'm wrong can somebody explain? :)