vm_method.c: should not modify frozen objects

* vm_method.c (rb_method_entry_make, remove_method): ditto.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@47551 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

4 files changed, 19 insertions, 2 deletions

diff --git a/ChangeLog b/ChangeLog
index 0994dc379d..e1cafee06b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Fri Sep 12 17:13:29 2014  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* vm_method.c (rb_method_entry_make, remove_method): ditto.
+
 Fri Sep 12 14:39:55 2014  SHIBATA Hiroshi  <shibata.hiroshi@gmail.com>
 
 	* gems/bundled_gems: Upgraded to test-unit-3.0.1 and minitest-5.4.1
diff --git a/eval.c b/eval.c
index 90da22503e..cd91a1a735 100644
--- a/eval.c
+++ b/eval.c
@@ -409,6 +409,10 @@ rb_frozen_class_p(VALUE klass)
       noclass:
 	Check_Type(klass, T_CLASS);
     }
+    if (FL_TEST(klass, FL_SINGLETON)) {
+	VALUE obj = rb_ivar_get(klass, id__attached__);
+	if (OBJ_FROZEN(obj)) OBJ_FREEZE(klass);
+    }
     if (OBJ_FROZEN(klass)) {
 	const char *desc;
 
diff --git a/test/ruby/test_class.rb b/test/ruby/test_class.rb
index 963c497d2f..9a4cdb0f58 100644
--- a/test/ruby/test_class.rb
+++ b/test/ruby/test_class.rb
@@ -384,4 +384,13 @@ class TestClass < Test::Unit::TestCase
       Class.new.freeze.clone.to_s
     }
   end
+
+  def test_singleton_class_of_frozen_object
+    obj = Object.new
+    c = obj.singleton_class
+    obj.freeze
+    assert_raise(RuntimeError, /frozen object/) {
+      c.class_eval {def f; end}
+    }
+  end
 end
diff --git a/vm_method.c b/vm_method.c
index 74dafab3f6..60b7dc0e8f 100644
--- a/vm_method.c
+++ b/vm_method.c
@@ -271,7 +271,7 @@ rb_method_entry_make(VALUE klass, ID mid, rb_method_type_t type,
 	}
     }
 
-    rb_check_frozen(klass);
+    rb_frozen_class_p(klass);
 #if NOEX_NOREDEF
     rklass = klass;
 #endif
@@ -746,7 +746,7 @@ remove_method(VALUE klass, ID mid)
     VALUE self = klass;
 
     klass = RCLASS_ORIGIN(klass);
-    rb_check_frozen(klass);
+    rb_frozen_class_p(klass);
     if (mid == object_id || mid == id__send__ || mid == idInitialize) {
 	rb_warn("removing `%s' may cause serious problems", rb_id2name(mid));
     }