AbstractController::Translation#t: dup options

actionpack/lib/abstract_controller/translation.rb

@@ -11,6 +11,7 @@ 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 == "."
         path = controller_path.tr("/", ".")
         defaults = [:"#{path}#{key}"]