t/close-has-env.ru in rainbows-4.6.2 vs t/close-has-env.ru in rainbows-4.7.0

@@ -8,9 +8,10 @@
     rv.env = env
     rv
   end
 
   def close
+    return if closed? # idempotent for Ruby 2.3.0 compatibility
     super
     $stdout.syswrite "path_info=#{@env['PATH_INFO']}\n"
   end
 end