monkey patch to rails 3.1 image functions

lib/compass/app_integration/rails/actionpack31/helpers.rb

@@ -3,3 +3,24 @@ module Sass::Script::Functions
     asset_url(path, Sass::Script::String.new("image"))
   end
 end
+
+
+module Compass::RailsImageFuctionPatch
+  private
+  
+  def image_path(image_file)
+    if file = Rails.application.assets.find_asset(image_file)
+      return file
+    end
+    super(image_file)
+  end
+end
+
+module Sass::Script::Functions
+  include Compass::RailsImageFuctionPatch
+end
+
+# Wierd that this has to be re-included to pick up sub-modules. Ruby bug?
+class Sass::Script::Functions::EvaluationContext
+  include Sass::Script::Functions
+end