rails/rails — pull request #4283 by lest (2012-01-03 20:47:17+00:00)
Title: use correct variant of checking whether class is a singleton

```
irb(main):008:0> klass = (class << Object.new; self end)
=> #>
irb(main):009:0> klass.ancestors.first == klass
=> false
irb(main):010:0> klass = Class.new
=> #
irb(main):011:0> klass.ancestors.first == klass
=> true
```