layout does not include application.xml.builder in rails 2.2/2.3

I have a lot of format.xml responses in my controllers. All of them renders with the default xml layout: application.xml.builder, which is simple xml.instruct!, followed by flash nodes, then the active records (to_xml). In rails 2.2/2.3, the layout has stopped rendering. I have googled and asked around without any luck. Would you please investigate? I wrote a simple rails app to illustrate the point:

I have one model - user.rb: class User < ActiveRecord::Base def name

"foo"

end end

and users_controller.rb: class UsersController < ApplicationController def index

respond_to do |format|
  format.html
  format.xml do
    render :xml => User.new, :layout => 'application'
  end
end

end end

I defined routes for it: map.resources :users

Then I change this to vary rails' versions for testing: RAILS_GEM_VERSION = '2.2.2' unless defined? RAILS_GEM_VERSION

Using :layout => 'application' or not doesn't matter. When I hit http://localhost:3000/users.xml I get this output:

Processing UsersController#index to xml (for 127.0.0.1 at 2009-03-16 17:41:10) [GET] [4;36;1mSQL (0.3ms) [0;1mSET SQL_AUTO_IS_NULL=0 [4;35;1mUser Columns (1.5ms) SHOW FIELDS FROM users Rendering template within layouts/application Completed in 34ms (View: 6, DB: 2) | 200 OK [http://localhost/ users.xml]

As you can see, it is renderin layouts/application.

I have defined views/layouts/application.xml.builder as such: xml.instruct!

xml.response do

xml << yield

end

And what I get is:

<created-at type="datetime" nil="true"/> <updated-at type="datetime" nil="true"/>

What I expect to get is xml instruct on top, then a response node, with user inside.