4 files changed, 43 insertions, 11 deletions
diff --git a/actionpack/lib/action_controller/base.rb b/actionpack/lib/action_controller/base.rb
index 2c7a223971..68a526eccb 100644
--- a/actionpack/lib/action_controller/base.rb
+++ b/actionpack/lib/action_controller/base.rb
@@ -217,7 +217,7 @@ module ActionController
       MimeResponds,
       ImplicitRender,
       StrongParameters,
-
+      ParameterEncoding,
       Cookies,
       Flash,
       FormBuilder,
diff --git a/actionpack/lib/action_controller/metal.rb b/actionpack/lib/action_controller/metal.rb
index 0364500944..075e4504c2 100644
--- a/actionpack/lib/action_controller/metal.rb
+++ b/actionpack/lib/action_controller/metal.rb
@@ -139,6 +139,10 @@ module ActionController
       end
     end
 
+    def self.encoding_for_param(action, param) # :nodoc:
+      ::Encoding::UTF_8
+    end
+
     # Delegates to the class' <tt>controller_name</tt>
     def controller_name
       self.class.controller_name
diff --git a/actionpack/lib/action_controller/metal/parameter_encoding.rb b/actionpack/lib/action_controller/metal/parameter_encoding.rb
new file mode 100644
index 0000000000..a278c5d011
--- /dev/null
+++ b/actionpack/lib/action_controller/metal/parameter_encoding.rb
@@ -0,0 +1,30 @@
+module ActionController
+  # Allows encoding to be specified per parameter per action.
+  module ParameterEncoding
+    extend ActiveSupport::Concern
+
+    module ClassMethods
+      def inherited(klass) # :nodoc:
+        super
+        klass.setup_param_encode
+      end
+
+      def setup_param_encode # :nodoc:
+        @_parameter_encodings = {}
+      end
+
+      def encoding_for_param(action, param) # :nodoc:
+        if @_parameter_encodings[action.to_s] && @_parameter_encodings[action.to_s][param.to_s]
+          @_parameter_encodings[action.to_s][param.to_s]
+        else
+          ::Encoding::UTF_8
+        end
+      end
+
+      def parameter_encoding(action, param_name, encoding)
+        @_parameter_encodings[action.to_s] ||= {}
+        @_parameter_encodings[action.to_s][param_name.to_s] = encoding
+      end
+    end
+  end
+end
diff --git a/actionpack/lib/action_controller/test_case.rb b/actionpack/lib/action_controller/test_case.rb
index ccedecd6f4..3a6bc92b3c 100644
--- a/actionpack/lib/action_controller/test_case.rb
+++ b/actionpack/lib/action_controller/test_case.rb
@@ -33,12 +33,14 @@ module ActionController
       TestSession.new
     end
 
+    attr_reader :controller_class
+
     # Create a new test request with default `env` values
-    def self.create
+    def self.create(controller_class)
       env = {}
       env = Rails.application.env_config.merge(env) if defined?(Rails.application) && Rails.application
       env["rack.request.cookie_hash"] = {}.with_indifferent_access
-      new(default_env.merge(env), new_session)
+      new(default_env.merge(env), new_session, controller_class)
     end
 
     def self.default_env
@@ -46,11 +48,12 @@ module ActionController
     end
     private_class_method :default_env
 
-    def initialize(env, session)
+    def initialize(env, session, controller_class)
       super(env)
 
       self.session = session
       self.session_options = TestSession::DEFAULT_OPTIONS
+      @controller_class = controller_class
       @custom_param_parsers = {
         xml: lambda { |raw_post| Hash.from_xml(raw_post)["hash"] }
       }
@@ -497,7 +500,7 @@ module ActionController
         @request.set_header "HTTP_COOKIE", cookies.to_header
         @request.delete_header "action_dispatch.cookies"
 
-        @request          = TestRequest.new scrub_env!(@request.env), @request.session
+        @request          = TestRequest.new scrub_env!(@request.env), @request.session, @controller.class
         @response         = build_response @response_klass
         @response.request = @request
         @controller.recycle!
@@ -591,7 +594,7 @@ module ActionController
           end
         end
 
-        @request          = TestRequest.create
+        @request          = TestRequest.create(@controller.class)
         @response         = build_response @response_klass
         @response.request = @request
 
@@ -668,11 +671,6 @@ module ActionController
             end
           end
         end
-
-        def html_format?(parameters)
-          return true unless parameters.key?(:format)
-          Mime.fetch(parameters[:format]) { Mime["html"] }.html?
-        end
     end
 
     include Behavior