Allow code execution in case no variant has been set with variant.none

actionpack/lib/action_controller/metal/mime_responds.rb

@@ -196,9 +196,10 @@ def clear_respond_to
     # Respond to variants in the action just like you respond to formats:
     #
     #   respond_to do |format|
-    #     format.html do |html|
-    #       html.tablet # renders app/views/projects/show.html+tablet.erb
-    #       html.phone { extra_setup; render ... }
+    #     format.html do |variant|
+    #       variant.tablet # renders app/views/projects/show.html+tablet.erb
+    #       variant.phone { extra_setup; render ... }
+    #       variant.none  { special_setup } # executed only if there is no variant set
     #     end
     #   end
     #
@@ -465,7 +466,7 @@ def initialize(variant)
         end
 
         def method_missing(name)
-          yield if name == @variant
+          yield if name == @variant || (name == :none && @variant.nil?)
         end
       end
     end

actionpack/test/controller/mime/respond_to_test.rb

@@ -166,6 +166,15 @@ def multiple_variants_for_format
     end
   end
 
+  def variant_plus_none_for_format
+    respond_to do |format|
+      format.html do |variant|
+        variant.phone { render text: "phone" }
+        variant.none  { render text: "none" }
+      end
+    end
+  end
+
   protected
     def set_layout
       case action_name
@@ -544,4 +553,11 @@ def test_multiple_variants_for_format
     assert_equal "text/html", @response.content_type
     assert_equal "tablet", @response.body
   end
+
+
+  def test_no_variant_in_variant_setup
+    get :variant_plus_none_for_format
+    assert_equal "text/html", @response.content_type
+    assert_equal "none", @response.body
+  end
 end