adding test to reproduce JRUBY-3917

module_redefinition.rb

@@ -0,0 +1,26 @@
+require 'rubygems'
+require 'minitest/autorun'
+
+class ModuleRedefinitionTest < MiniTest::Unit::TestCase
+  class Foo
+    private
+    def foo
+      p :foo
+    end
+  end
+
+  class Bar < Foo
+    public :foo
+  end
+
+  class Foo
+    def foo
+      p :redefined
+    end
+  end
+
+  def test_module_redefinition
+    b = Bar.new
+    assert_equal b.foo, :redefined
+  end
+end