解决方法
有一个
blog post,您可以阅读单个CHANGELOG文件
> https://github.com/rails/rails/blob/3-0-4-security/actionmailer/CHANGELOG
> https://github.com/rails/rails/blob/3-0-4-security/actionpack/CHANGELOG
> https://github.com/rails/rails/blob/3-0-4-security/activemodel/CHANGELOG
> https://github.com/rails/rails/blob/3-0-4-security/activerecord/CHANGELOG
> https://github.com/rails/rails/blob/3-0-4-security/activeresource/CHANGELOG
> https://github.com/rails/rails/blob/3-0-4-security/activesupport/CHANGELOG
> https://github.com/rails/rails/blob/3-0-4-security/railties/CHANGELOG
您还可以比较3.0.3和3.0.4之间的变化