Allow specifying encoding of parameters by action

At GitHub we need to handle parameter encodings that are not UTF-8. This
patch allows us to specify encodings per parameter per action.

3 files changed, 18 insertions, 1 deletions

diff --git a/actionpack/lib/action_dispatch/http/parameters.rb b/actionpack/lib/action_dispatch/http/parameters.rb
index f25e50f9f3..a9d1a501ab 100644
--- a/actionpack/lib/action_dispatch/http/parameters.rb
+++ b/actionpack/lib/action_dispatch/http/parameters.rb
@@ -37,11 +37,23 @@ module ActionDispatch
                    query_parameters.dup
                  end
         params.merge!(path_parameters)
+        params = set_custom_encoding(params)
         set_header("action_dispatch.request.parameters", params)
         params
       end
       alias :params :parameters
 
+      def set_custom_encoding(params)
+        action = params[:action]
+        params.each do |k, v|
+          if v.is_a?(String) && v.encoding != encoding_template(action, k)
+            params[k] = v.force_encoding(encoding_template(action, k))
+          end
+        end
+
+        params
+      end
+
       def path_parameters=(parameters) #:nodoc:
         delete_header("action_dispatch.request.parameters")
 
@@ -64,6 +76,10 @@ module ActionDispatch
 
       private
 
+        def encoding_template(action, param)
+          controller_class.encoding_for_param(action, param)
+        end
+
         def parse_formatted_parameters(parsers)
           return yield if content_length.zero? || content_mime_type.nil?
 
diff --git a/actionpack/lib/action_dispatch/http/request.rb b/actionpack/lib/action_dispatch/http/request.rb
index 46409a325e..e7cc6d5f31 100644
--- a/actionpack/lib/action_dispatch/http/request.rb
+++ b/actionpack/lib/action_dispatch/http/request.rb
@@ -69,6 +69,7 @@ module ActionDispatch
     PASS_NOT_FOUND = Class.new { # :nodoc:
       def self.action(_); self; end
       def self.call(_); [404, {"X-Cascade" => "pass"}, []]; end
+      def self.encoding_for_param(action, param); ::Encoding::UTF_8; end
     }
 
     def controller_class
diff --git a/actionpack/lib/action_dispatch/testing/assertions/routing.rb b/actionpack/lib/action_dispatch/testing/assertions/routing.rb
index cba67b2839..2ea4a6c130 100644
--- a/actionpack/lib/action_dispatch/testing/assertions/routing.rb
+++ b/actionpack/lib/action_dispatch/testing/assertions/routing.rb
@@ -184,7 +184,7 @@ module ActionDispatch
           end
 
           # Assume given controller
-          request = ActionController::TestRequest.create
+          request = ActionController::TestRequest.create @controller.class
 
           if path =~ %r{://}
             fail_on(URI::InvalidURIError, msg) do