diff --git a/ChangeLog b/ChangeLog
index 5598c3b186..924007ab4d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Mon Dec 28 22:00:10 2009  NAKAMURA, Hiroshi  <nahi@ruby-lang.org>
+
+	* test/ruby/test_marshal.rb: added tests for taintness/untrustness
+	  propagation.
+
 Mon Dec 28 18:13:26 2009  Yuki Sonoda (Yugui)  <yugui@yugui.jp>
 
 	* sample/occur2.rb: reimplemented in modern style. [ruby-dev:39927].
diff --git a/test/ruby/test_marshal.rb b/test/ruby/test_marshal.rb
index 12d1bff30c..704385897c 100644
--- a/test/ruby/test_marshal.rb
+++ b/test/ruby/test_marshal.rb
@@ -193,6 +193,70 @@ class TestMarshal < Test::Unit::TestCase
     assert_equal(true, y.untrusted?)
   end
 
+  def test_taint_and_untrust_each_object
+    x = Object.new
+    obj = [[x]]
+
+    # clean object causes crean stream
+    assert_equal(false, obj.tainted?)
+    assert_equal(false, obj.untrusted?)
+    assert_equal(false, obj.first.tainted?)
+    assert_equal(false, obj.first.untrusted?)
+    assert_equal(false, obj.first.first.tainted?)
+    assert_equal(false, obj.first.first.untrusted?)
+    s = Marshal.dump(obj)
+    assert_equal(false, s.tainted?)
+    assert_equal(false, s.untrusted?)
+
+    # tainted/untrusted object causes tainted/untrusted stream
+    x.taint
+    x.untrust
+    assert_equal(false, obj.tainted?)
+    assert_equal(false, obj.untrusted?)
+    assert_equal(false, obj.first.tainted?)
+    assert_equal(false, obj.first.untrusted?)
+    assert_equal(true, obj.first.first.tainted?)
+    assert_equal(true, obj.first.first.untrusted?)
+    t = Marshal.dump(obj)
+    assert_equal(true, t.tainted?)
+    assert_equal(true, t.untrusted?)
+
+    # clean stream causes clean objects
+    assert_equal(false, s.tainted?)
+    assert_equal(false, s.untrusted?)
+    y = Marshal.load(s)
+    assert_equal(false, y.tainted?)
+    assert_equal(false, y.untrusted?)
+    assert_equal(false, y.first.tainted?)
+    assert_equal(false, y.first.untrusted?)
+    assert_equal(false, y.first.first.tainted?)
+    assert_equal(false, y.first.first.untrusted?)
+
+    # tainted/untrusted stream causes tainted/untrusted objects
+    assert_equal(true, t.tainted?)
+    assert_equal(true, t.untrusted?)
+    y = Marshal.load(t)
+    assert_equal(true, y.tainted?)
+    assert_equal(true, y.untrusted?)
+    assert_equal(true, y.first.tainted?)
+    assert_equal(true, y.first.untrusted?)
+    assert_equal(true, y.first.first.tainted?)
+    assert_equal(true, y.first.first.untrusted?)
+
+    # same tests by different senario
+    s.taint
+    s.untrust
+    assert_equal(true, s.tainted?)
+    assert_equal(true, s.untrusted?)
+    y = Marshal.load(s)
+    assert_equal(true, y.tainted?)
+    assert_equal(true, y.untrusted?)
+    assert_equal(true, y.first.tainted?)
+    assert_equal(true, y.first.untrusted?)
+    assert_equal(true, y.first.first.tainted?)
+    assert_equal(true, y.first.first.untrusted?)
+  end
+
   def test_symbol
     [:ruby, :"\u{7d05}\u{7389}"].each do |sym|
       assert_equal(sym, Marshal.load(Marshal.dump(sym)), '[ruby-core:24788]')