Rack::Test doesn't pass a request body for GET requests?

rack_test.rb

        if env["REQUEST_METHOD"] == "GET"
          # merge :params with the query string
          if params = env[:params]
            params = parse_nested_query(params) if params.is_a?(String)
            params.update(parse_nested_query(uri.query))
            uri.query = build_nested_query(params)
          end

test result

$ ruby test_get_body.rb
Run options: 

# Running tests:

.F

Finished tests in 0.092553s, 21.6093 tests/s, 21.6093 assertions/s.

  1) Failure:
test_02_get_body(GetBodyTest) [test_get_body.rb:31]:
<"wtf\n"> expected but was
<"\n">.

2 tests, 2 assertions, 1 failures, 0 errors, 0 skips

test_get_body.rb

require 'sinatra'
require 'test/unit'
require 'rack/test'

ENV['RACK_ENV'] = 'test'

class GetBody < Sinatra::Application
  get '/' do
    request.body.read + "\n"
  end

  post '/' do
    request.body.read + "\n"
  end
end

class GetBodyTest < Test::Unit::TestCase
  include Rack::Test::Methods

  def app
    GetBody
  end

  def test_01_post_body
    r = post '/', "wtf"
    assert_equal "wtf\n", last_response.body
  end

  def test_02_get_body
    r = get '/', 'wtf'
    assert_equal "wtf\n", last_response.body
  end
end