Fix controller test not resetting @_url_options

Commit 4f2cd3e9 introduced a bug by reordering the call to
`@controller.recycle!` above the call to `build_request_uri`. The
impact of this was that the `@_url_options` cache ends up not being
reset between building a request URI (occurring within the test
controller) and the firing of the actual request.

We encountered this bug because we had the following setup:

  class MinimumReproducibleController < ActionController::Base
    before_filter { @param = 'param' }

    def index
      render text: url_for(params)
    end

    def default_url_options
      { custom_opt: @param }
    end
  end

  def test_index
    get :index # builds url, then fires actual request
  end

The first step in  `get :index` in the test suite would populate the
@_url_options cache. The subsequent call to `url_for` inside of the
controller action would then utilize the uncleared cache, thus never
calling the now-updated default_url_options.

This commit fixes this bug calling recycle! twice, and removes a call
to set response_body, which should no longer be needed since we're
recycling the request object explicitly.

4 files changed, 29 insertions, 1 deletions

diff --git a/actionpack/CHANGELOG.md b/actionpack/CHANGELOG.md
index 68b5213bfc..66cef08b1b 100644
--- a/actionpack/CHANGELOG.md
+++ b/actionpack/CHANGELOG.md
@@ -1 +1,6 @@
+*   Fix URL generation in controller tests with request-dependent
+    `default_url_options` methods.
+
+    *Tony Wooster*
+
 Please check [4-1-stable](https://github.com/rails/rails/blob/4-1-stable/actionpack/CHANGELOG.md) for previous changes.
diff --git a/actionpack/lib/action_controller/metal/testing.rb b/actionpack/lib/action_controller/metal/testing.rb
index 0377b8c4cf..dd8da4b5dc 100644
--- a/actionpack/lib/action_controller/metal/testing.rb
+++ b/actionpack/lib/action_controller/metal/testing.rb
@@ -17,7 +17,6 @@ module ActionController
 
       def recycle!
         @_url_options = nil
-        self.response_body = nil
         self.formats = nil
         self.params = nil
       end
diff --git a/actionpack/lib/action_controller/test_case.rb b/actionpack/lib/action_controller/test_case.rb
index cf11ce1a9b..8650b75400 100644
--- a/actionpack/lib/action_controller/test_case.rb
+++ b/actionpack/lib/action_controller/test_case.rb
@@ -568,6 +568,7 @@ module ActionController
 
         name = @request.parameters[:action]
 
+        @controller.recycle!
         @controller.process(name)
 
         if cookies = @request.env['action_dispatch.cookies']
diff --git a/actionpack/test/controller/test_case_test.rb b/actionpack/test/controller/test_case_test.rb
index 5ff4a383ec..fbc10baf21 100644
--- a/actionpack/test/controller/test_case_test.rb
+++ b/actionpack/test/controller/test_case_test.rb
@@ -163,6 +163,29 @@ XML
     end
   end
 
+  class DefaultUrlOptionsCachingController < ActionController::Base
+    before_filter { @dynamic_opt = 'opt' }
+
+    def test_url_options_reset
+      render text: url_for(params)
+    end
+
+    def default_url_options
+      if defined?(@dynamic_opt)
+        super.merge dynamic_opt: @dynamic_opt
+      else
+        super
+      end
+    end
+  end
+
+  def test_url_options_reset
+    @controller = DefaultUrlOptionsCachingController.new
+    get :test_url_options_reset
+    assert_nil @request.params['dynamic_opt']
+    assert_match(/dynamic_opt=opt/, @response.body)
+  end
+
   def test_raw_post_handling
     params = Hash[:page, {:name => 'page name'}, 'some key', 123]
     post :render_raw_post, params.dup