No need to dup before double-splatting a Hash

activesupport/lib/active_support/option_merger.rb

@@ -21,7 +21,7 @@ module ActiveSupport
         elsif arguments.last.respond_to?(:to_hash)
           options = @options.deep_merge(arguments.pop)
         else
-          options = @options.dup
+          options = @options
         end
 
         if options