From 59f5fa102af7777ba1c620b764fa05f62dad9b54 Mon Sep 17 00:00:00 2001
From: shugo <shugo@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Mon, 30 Sep 2013 01:49:21 +0000
Subject: [PATCH] * 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
---
 ChangeLog                    |  9 ++++++++
 test/ruby/test_refinement.rb | 44 ++++++++++++++++++++++++++++++++++++
 vm_method.c                  |  8 ++++---
 3 files changed, 58 insertions(+), 3 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 3963ed9fa2..6f74a14769 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+Mon Sep 30 10:40:20 2013  Shugo Maeda  <shugo@ruby-lang.org>
+
+	* 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.
+
 Sun Sep 29 23:45:42 2013  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* parse.y (rb_id_attrset, intern_str): allow junk attrset ID for
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)
diff --git a/vm_method.c b/vm_method.c
index e4ba0e9865..8bd2b2ce56 100644
--- a/vm_method.c
+++ b/vm_method.c
@@ -868,7 +868,9 @@ rb_undef(VALUE klass, ID id)
 
     me = search_method(klass, id, 0);
 
-    if (UNDEFINED_METHOD_ENTRY_P(me)) {
+    if (UNDEFINED_METHOD_ENTRY_P(me) ||
+	(me->def->type == VM_METHOD_TYPE_REFINED &&
+	 UNDEFINED_METHOD_ENTRY_P(me->def->body.orig_me))) {
 	const char *s0 = " class";
 	VALUE c = klass;
 
@@ -1118,9 +1120,9 @@ rb_method_entry_eq(const rb_method_entry_t *m1, const rb_method_entry_t *m2)
 static int
 rb_method_definition_eq(const rb_method_definition_t *d1, const rb_method_definition_t *d2)
 {
-    if (d1 && d1->type == VM_METHOD_TYPE_REFINED)
+    if (d1 && d1->type == VM_METHOD_TYPE_REFINED && d1->body.orig_me)
 	d1 = d1->body.orig_me->def;
-    if (d2 && d2->type == VM_METHOD_TYPE_REFINED)
+    if (d2 && d2->type == VM_METHOD_TYPE_REFINED && d2->body.orig_me)
 	d2 = d2->body.orig_me->def;
     if (d1 == d2) return 1;
     if (!d1 || !d2) return 0;