Bring layouts with proc back alive.

actionpack/lib/abstract_controller/layouts.rb

@@ -270,6 +270,9 @@ def _layout(details)
               end
             end
           ruby_eval
+        when Proc
+          define_method :_layout_from_proc, &@_layout
+          self.class_eval %{def _layout(details) _layout_from_proc(self) end}
         when false
           self.class_eval %{def _layout(details) end}
         when true

actionpack/test/abstract/layouts_test.rb

@@ -67,7 +67,15 @@ class WithStringImpliedChild < WithString
     
     class WithChildOfImplied < WithStringImpliedChild
     end
-    
+
+    class WithProc < Base
+      layout proc { |c| "omg" }
+
+      def index
+        render :_template => ActionView::Template::Text.new("Hello proc!")
+      end
+    end
+
     class WithSymbol < Base
       layout :hello
       
@@ -198,6 +206,12 @@ class TestBase < ActiveSupport::TestCase
         controller.process(:index)
         assert_equal "Hello nil!", controller.response_body
       end
+
+      test "when layout is specified as a proc, call it and use the layout returned" do
+        controller = WithProc.new
+        controller.process(:index)
+        assert_equal "OMGHI2U Hello proc!", controller.response_body
+      end
       
       test "when layout is specified as a symbol, call the requested method and use the layout returned" do
         controller = WithSymbol.new