class.c: do not freeze meta-meta-class

* class.c (rb_freeze_singleton_class): should not propagate to
  meta-meta-class, and so on, which is shared with the original
  class.  fix occational exceptions.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@47633 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 12 insertions, 3 deletions

diff --git a/test/ruby/test_module.rb b/test/ruby/test_module.rb
index 95758aa6d4..ce5ab2ff73 100644
--- a/test/ruby/test_module.rb
+++ b/test/ruby/test_module.rb
@@ -914,25 +914,34 @@ class TestModule < Test::Unit::TestCase
     assert_include(c.constants(false), :Foo, bug9413)
   end
 
-  def test_frozen_class
+  def test_frozen_module
     m = Module.new
     m.freeze
     assert_raise(RuntimeError) do
       m.instance_eval { undef_method(:foo) }
     end
+  end
 
+  def test_frozen_class
     c = Class.new
     c.freeze
     assert_raise(RuntimeError) do
       c.instance_eval { undef_method(:foo) }
     end
+  end
 
-    o = Object.new
+  def test_frozen_singleton_class
+    klass = Class.new
+    o = klass.new
     c = class << o; self; end
     c.freeze
-    assert_raise(RuntimeError) do
+    assert_raise_with_message(RuntimeError, /frozen/) do
       c.instance_eval { undef_method(:foo) }
     end
+    klass.class_eval do
+      def self.foo
+      end
+    end
   end
 
   def test_method_defined