Adding a test for initialize_clone and initialize_dup. From Github:

tenderlove · tenderlove · commit 5d316e778643 · 2012-10-05T16:22:03.000Z
ruby#190 git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@37100 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
diff --git a/test/ruby/test_object.rb b/test/ruby/test_object.rb
@@ -21,6 +21,17 @@ def test_dup
     end
   end
 
+  def test_init_dupclone
+    cls = Class.new do
+      def initialize_clone(orig); throw :initialize_clone; end
+      def initialize_dup(orig); throw :initialize_dup; end
+    end
+
+    obj = cls.new
+    assert_throws(:initialize_clone) {obj.clone}
+    assert_throws(:initialize_dup) {obj.dup}
+  end
+
   def test_instance_of
     assert_raise(TypeError) { 1.instance_of?(1) }
   end
