Maybe Capybara <-> Nokogiri bug, inserting extra xml declaration

capybara_nokogiri_xml_declaration_problem.rb

# coding: utf-8
require 'capybara'
require 'capybara/rspec'
require 'sinatra'

class TestApp < Sinatra::Base
  set :root, File.dirname(__FILE__)
  set :static, true

  get '/' do
    'Hello world!'
  end

  get '/iframe_content' do
    '<iframe src=\"xx.html\"></iframe>'
  end

  get '/accented_content' do
    '¡Leñe!'
  end
  
end

describe "Capybara inserts <?xml version=\"1.0\" standalone=\"yes\"?> line" do
  before do
    Capybara.app = TestApp
  end

  let(:session) { Capybara::Session.new(:rack_test, TestApp) }
  
  it "and this breaks '<iframe></iframe>' parsing, for example" do
    session.visit('/iframe_content')
    session.body.should =~ /<iframe.*<\/iframe>/
  end

  it "it also breaks accented characters" do
    session.visit('/accented_content')
    session.body.should include("¡Leñe!")
  end

  it "this will work in places with xml header, but not in others" do
    session.visit('/accented_content')
    session.body.should include("&#xA1;Le&#xF1;e!")
  end
  
end