* vm_method.c (rb_undef): raise a NameError if the original method

  of a refined method is not defined.

* vm_insnhelper.c (rb_method_entry_eq): added NULL check to avoid SEGV.

* test/ruby/test_refinement.rb: related test.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@43090 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 44 insertions, 0 deletions

diff --git a/test/ruby/test_refinement.rb b/test/ruby/test_refinement.rb
index 60681b2f1a..92f293cad5 100644
--- a/test/ruby/test_refinement.rb
+++ b/test/ruby/test_refinement.rb
@@ -1016,6 +1016,50 @@ class TestRefinement < Test::Unit::TestCase
     assert_not_send([FooSub, :method_defined?, :z])
   end
 
+  def test_undef_refined_method
+    bug8966 = '[ruby-core:57466] [Bug #8966]'
+
+    assert_in_out_err([], <<-INPUT, ["NameError"], [], bug8966)
+      module Foo
+        refine Object do
+          def foo
+            puts "foo"
+          end
+        end
+      end
+
+      using Foo
+
+      class Object
+        begin
+          undef foo
+        rescue Exception => e
+          p e.class
+        end
+      end
+    INPUT
+
+    assert_in_out_err([], <<-INPUT, ["NameError"], [], bug8966)
+      module Foo
+        refine Object do
+          def foo
+            puts "foo"
+          end
+        end
+      end
+
+      # without `using Foo'
+
+      class Object
+        begin
+          undef foo
+        rescue Exception => e
+          p e.class
+        end
+      end
+    INPUT
+  end
+
   private
 
   def eval_using(mod, s)