Kernel.extend now raises a TypeError, when called on a frozen object

From 39899b7c48c272a6c049d2baf7411ed13eaed880 Mon Sep 17 00:00:00 2001
From: Jose Narvaez <goyox86@gmail.com>
Date: Sun, 18 Jul 2010 16:03:12 -0430
Subject: [PATCH 2/2] Kernel.extend now raises a TypeError, when called on a frozen object

---
 kernel/common/kernel.rb |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/kernel/common/kernel.rb b/kernel/common/kernel.rb
index fb897af..1471100 100644
--- a/kernel/common/kernel.rb
+++ b/kernel/common/kernel.rb
@@ -380,6 +380,8 @@ module Kernel
   end
 
   def extend(*modules)
+    Ruby.check_frozen
+    
     modules.reverse_each do |mod|
       mod.__send__(:extend_object, self)
       mod.__send__(:extended, self)
-- 
1.7.0.3