Add RewindableInput wrapper to fix issues with middleware that impolitely eat up non-rewindable input

5 files changed, 128 insertions, 8 deletions

diff --git a/actionpack/lib/action_controller.rb b/actionpack/lib/action_controller.rb
index 8c022e5625..0d81b9c346 100644
--- a/actionpack/lib/action_controller.rb
+++ b/actionpack/lib/action_controller.rb
@@ -59,16 +59,14 @@ module ActionController
   autoload :MiddlewareStack, 'action_controller/middleware_stack'
   autoload :MimeResponds, 'action_controller/mime_responds'
   autoload :PolymorphicRoutes, 'action_controller/polymorphic_routes'
-  autoload :Request, 'action_controller/request'
-  autoload :RequestParser, 'action_controller/request_parser'
-  autoload :UrlEncodedPairParser, 'action_controller/url_encoded_pair_parser'
-  autoload :UploadedStringIO, 'action_controller/uploaded_file'
-  autoload :UploadedTempfile, 'action_controller/uploaded_file'
   autoload :RecordIdentifier, 'action_controller/record_identifier'
-  autoload :Response, 'action_controller/response'
+  autoload :Request, 'action_controller/request'
   autoload :RequestForgeryProtection, 'action_controller/request_forgery_protection'
+  autoload :RequestParser, 'action_controller/request_parser'
   autoload :Rescue, 'action_controller/rescue'
   autoload :Resources, 'action_controller/resources'
+  autoload :Response, 'action_controller/response'
+  autoload :RewindableInput, 'action_controller/rewindable_input'
   autoload :Routing, 'action_controller/routing'
   autoload :SessionManagement, 'action_controller/session_management'
   autoload :StatusCodes, 'action_controller/status_codes'
@@ -76,6 +74,9 @@ module ActionController
   autoload :TestCase, 'action_controller/test_case'
   autoload :TestProcess, 'action_controller/test_process'
   autoload :Translation, 'action_controller/translation'
+  autoload :UploadedStringIO, 'action_controller/uploaded_file'
+  autoload :UploadedTempfile, 'action_controller/uploaded_file'
+  autoload :UrlEncodedPairParser, 'action_controller/url_encoded_pair_parser'
   autoload :UrlRewriter, 'action_controller/url_rewriter'
   autoload :UrlWriter, 'action_controller/url_rewriter'
   autoload :VerbPiggybacking, 'action_controller/verb_piggybacking'
diff --git a/actionpack/lib/action_controller/middlewares.rb b/actionpack/lib/action_controller/middlewares.rb
index 793739723f..914750bc0c 100644
--- a/actionpack/lib/action_controller/middlewares.rb
+++ b/actionpack/lib/action_controller/middlewares.rb
@@ -18,4 +18,5 @@ use "ActiveRecord::QueryCache", :if => lambda { defined?(ActiveRecord) }
     )
 end
 
+use ActionController::RewindableInput
 use ActionController::VerbPiggybacking
diff --git a/actionpack/lib/action_controller/rewindable_input.rb b/actionpack/lib/action_controller/rewindable_input.rb
new file mode 100644
index 0000000000..296d8aed22
--- /dev/null
+++ b/actionpack/lib/action_controller/rewindable_input.rb
@@ -0,0 +1,40 @@
+module ActionController
+  class RewindableInput
+    class RewindableIO < ActiveSupport::BasicObject
+      def initialize(io)
+        @io = io
+      end
+
+      def read(*args)
+        read_original_io
+        @io.read(*args)
+      end
+
+      def rewind
+        read_original_io
+        @io.rewind
+      end
+
+      def method_missing(method, *args, &block)
+        @io.send(method, *args, &block)
+      end
+
+      private
+        def read_original_io
+          unless @str
+            @str = @io.read
+            @io = StringIO.new(@str)
+          end
+        end
+    end
+
+    def initialize(app)
+      @app = app
+    end
+
+    def call(env)
+      env['rack.input'] = RewindableIO.new(env['rack.input'])
+      @app.call(env)
+    end
+  end
+end
diff --git a/actionpack/test/controller/request/multipart_params_parsing_test.rb b/actionpack/test/controller/request/multipart_params_parsing_test.rb
index ce28ff46fe..d976ab8512 100644
--- a/actionpack/test/controller/request/multipart_params_parsing_test.rb
+++ b/actionpack/test/controller/request/multipart_params_parsing_test.rb
@@ -123,14 +123,14 @@ class MultipartParamsParsingTest < ActionController::IntegrationTest
   InputWrapper = Rack::Lint::InputWrapper
 
   test "parses unwindable stream" do
-    InputWrapper.any_instance.expects(:rewind).raises(Errno::ESPIPE)
+    InputWrapper.any_instance.stubs(:rewind).raises(Errno::ESPIPE)
     params = parse_multipart('large_text_file')
     assert_equal %w(file foo), params.keys.sort
     assert_equal 'bar', params['foo']
   end
 
   test "uploads and reads file with unwindable input" do
-    InputWrapper.any_instance.expects(:rewind).raises(Errno::ESPIPE)
+    InputWrapper.any_instance.stubs(:rewind).raises(Errno::ESPIPE)
 
     with_test_routing do
       post '/read', :uploaded_data => fixture_file_upload(FIXTURE_PATH + "/hello.txt", "text/plain")
@@ -138,6 +138,26 @@ class MultipartParamsParsingTest < ActionController::IntegrationTest
     end
   end
 
+  test "passes through rack middleware and uploads file" do
+    with_muck_middleware do
+      with_test_routing do
+        post '/read', :uploaded_data => fixture_file_upload(FIXTURE_PATH + "/hello.txt", "text/plain")
+        assert_equal "File: Hello", response.body
+      end
+    end
+  end
+
+  test "passes through rack middleware and uploads file with unwindable input" do
+    InputWrapper.any_instance.stubs(:rewind).raises(Errno::ESPIPE)
+
+    with_muck_middleware do
+      with_test_routing do
+        post '/read', :uploaded_data => fixture_file_upload(FIXTURE_PATH + "/hello.txt", "text/plain")
+        assert_equal "File: Hello", response.body
+      end
+    end
+  end
+
   private
     def fixture(name)
       File.open(File.join(FIXTURE_PATH, name), 'rb') do |file|
@@ -164,4 +184,25 @@ class MultipartParamsParsingTest < ActionController::IntegrationTest
         yield
       end
     end
+
+    class MuckMiddleware
+      def initialize(app)
+        @app = app
+      end
+
+      def call(env)
+        req = Rack::Request.new(env)
+        req.params # Parse params
+        @app.call(env)
+      end
+    end
+
+    def with_muck_middleware
+      original_middleware = ActionController::Dispatcher.middleware
+      middleware = original_middleware.dup
+      middleware.use MuckMiddleware
+      ActionController::Dispatcher.middleware = middleware
+      yield
+      ActionController::Dispatcher.middleware = original_middleware
+    end
 end
diff --git a/actionpack/test/controller/request/url_encoded_params_parsing_test.rb b/actionpack/test/controller/request/url_encoded_params_parsing_test.rb
index 26a4538ca6..b162796e5b 100644
--- a/actionpack/test/controller/request/url_encoded_params_parsing_test.rb
+++ b/actionpack/test/controller/request/url_encoded_params_parsing_test.rb
@@ -150,8 +150,45 @@ class UrlEncodedParamsParsingTest < ActionController::IntegrationTest
     assert_parses expected, query
   end
 
+  test "passes through rack middleware and parses params" do
+    with_muck_middleware do
+      assert_parses({ "a" => { "b" => "c" } }, "a[b]=c")
+    end
+  end
+
+  # The lint wrapper is used in integration tests
+  # instead of a normal StringIO class
+  InputWrapper = Rack::Lint::InputWrapper
+
+  test "passes through rack middleware and parses params with unwindable input" do
+    InputWrapper.any_instance.stubs(:rewind).raises(Errno::ESPIPE)
+    with_muck_middleware do
+      assert_parses({ "a" => { "b" => "c" } }, "a[b]=c")
+    end
+  end
 
   private
+    class MuckMiddleware
+      def initialize(app)
+        @app = app
+      end
+
+      def call(env)
+        req = Rack::Request.new(env)
+        req.params # Parse params
+        @app.call(env)
+      end
+    end
+
+    def with_muck_middleware
+      original_middleware = ActionController::Dispatcher.middleware
+      middleware = original_middleware.dup
+      middleware.use MuckMiddleware
+      ActionController::Dispatcher.middleware = middleware
+      yield
+      ActionController::Dispatcher.middleware = original_middleware
+    end
+
     def with_test_routing
       with_routing do |set|
         set.draw do |map|