How should I upgrade a Rails app to use the latest version of Rails

Question

I\'m working on a Rails app that currently uses Rails 1.2, so I\'m now quite a long way behind the latest stable release (Rails 2.3).

How should I go about the process o

Answer 1

I shall start by answering my own question with the resources that I've managed to turn up with my Googling. The Rails 2.2 release note and Rails 2.3 release note give details of new and changed features in these two releases, but I can't find anything so definitive for earlier releases.

I also haven't found much about what will break when upgrading, apart from this release announcement which mentions that older versions of Passenger won't work with Rails 2.3.