No need to dup options hash where it's not modified

actionpack/lib/abstract_controller/translation.rb

@@ -11,8 +11,8 @@ module Translation
     # to translate many keys within the same controller / action and gives you a
     # simple framework for scoping them consistently.
     def translate(key, options = {})
-      options = options.dup
       if key.to_s.first == "."
+        options = options.dup
         path = controller_path.tr("/", ".")
         defaults = [:"#{path}#{key}"]
         defaults << options[:default] if options[:default]