Allow layout fallback when using `layout` method

Rails will now use your default layout (such as "layouts/application") when you specify a layout with `:only` and `:except` condition, and those conditions fail.

For example, consider this snippet:

    class CarsController
      layout 'single_car', :only => :show
    end

Rails will use 'layouts/single_car' when a request comes in `:show` action, and use 'layouts/application' (or 'layouts/cars', if exists) when a request comes in for any other actions.

1 files changed, 49 insertions, 1 deletions

diff --git a/actionpack/test/abstract/layouts_test.rb b/actionpack/test/abstract/layouts_test.rb
index 86208899f8..a5382a730d 100644
--- a/actionpack/test/abstract/layouts_test.rb
+++ b/actionpack/test/abstract/layouts_test.rb
@@ -141,6 +141,30 @@ module AbstractControllerTests
       end
     end
 
+    class WithOnlyConditional < WithStringImpliedChild
+      layout "overwrite", :only => :show
+
+      def index
+        render :template => ActionView::Template::Text.new("Hello index!")
+      end
+
+      def show
+        render :template => ActionView::Template::Text.new("Hello show!")
+      end
+    end
+
+    class WithExceptConditional < WithStringImpliedChild
+      layout "overwrite", :except => :show
+
+      def index
+        render :template => ActionView::Template::Text.new("Hello index!")
+      end
+
+      def show
+        render :template => ActionView::Template::Text.new("Hello show!")
+      end
+    end
+
     class TestBase < ActiveSupport::TestCase
       test "when no layout is specified, and no default is available, render without a layout" do
         controller = Blank.new
@@ -260,6 +284,30 @@ module AbstractControllerTests
           end
         end
       end
+
+      test "when specify an :only option which match current action name" do
+        controller = WithOnlyConditional.new
+        controller.process(:show)
+        assert_equal "Overwrite Hello show!", controller.response_body
+      end
+
+      test "when specify an :only option which does not match current action name" do
+        controller = WithOnlyConditional.new
+        controller.process(:index)
+        assert_equal "With Implied Hello index!", controller.response_body
+      end
+
+      test "when specify an :except option which match current action name" do
+        controller = WithExceptConditional.new
+        controller.process(:show)
+        assert_equal "With Implied Hello show!", controller.response_body
+      end
+
+      test "when specify an :except option which does not match current action name" do
+        controller = WithExceptConditional.new
+        controller.process(:index)
+        assert_equal "Overwrite Hello index!", controller.response_body
+      end
     end
   end
-end
\ No newline at end of file
+end