Document and update API for `skip_parameter_encoding`

This commit changes `parameter_encoding` to `skip_parameter_encoding`.
`skip_parameter_encoding` will set encoding on all parameters to
ASCII-8BIT for a given action on a particular controller.  This allows
the controller to handle data when the encoding of that data is unknown,
for example file systems or truly binary parameters.

3 files changed, 17 insertions, 11 deletions

diff --git a/actionpack/lib/action_dispatch/http/parameters.rb b/actionpack/lib/action_dispatch/http/parameters.rb
index ddd15b748b..ad4aadacf5 100644
--- a/actionpack/lib/action_dispatch/http/parameters.rb
+++ b/actionpack/lib/action_dispatch/http/parameters.rb
@@ -45,7 +45,7 @@ module ActionDispatch
                    query_parameters.dup
                  end
         params.merge!(path_parameters)
-        params = set_custom_encoding(params)
+        params = set_binary_encoding(params)
         set_header("action_dispatch.request.parameters", params)
         params
       end
@@ -73,21 +73,16 @@ module ActionDispatch
 
       private
 
-        def set_custom_encoding(params)
+        def set_binary_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))
+          if controller_class.binary_params_for?(action)
+            ActionDispatch::Request::Utils.each_param_value(params) do |param|
+              param.force_encoding ::Encoding::ASCII_8BIT
             end
           end
-
           params
         end
 
-        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 9986d6e1e9..a886358399 100644
--- a/actionpack/lib/action_dispatch/http/request.rb
+++ b/actionpack/lib/action_dispatch/http/request.rb
@@ -69,7 +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 self.binary_params_for?(action); false; end
     }
 
     def controller_class
diff --git a/actionpack/lib/action_dispatch/request/utils.rb b/actionpack/lib/action_dispatch/request/utils.rb
index 282bdbd2be..01bc871e5f 100644
--- a/actionpack/lib/action_dispatch/request/utils.rb
+++ b/actionpack/lib/action_dispatch/request/utils.rb
@@ -4,6 +4,17 @@ module ActionDispatch
       mattr_accessor :perform_deep_munge
       self.perform_deep_munge = true
 
+      def self.each_param_value(params, &block)
+        case params
+        when Array
+          params.each { |element| each_param_value(element, &block) }
+        when Hash
+          params.each_value { |value| each_param_value(value, &block) }
+        when String
+          block.call params
+        end
+      end
+
       def self.normalize_encode_params(params)
         if perform_deep_munge
           NoNilParamEncoder.normalize_encode_params params