From 38e05ff3e194268fd2f38ac7c9530298e464f07b Mon Sep 17 00:00:00 2001
From: ko1 <ko1@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Mon, 9 Jul 2018 08:07:26 +0000
Subject: [PATCH] Don't copy FL_USER* on Kernel#clone. [Bug #14847]

* object.c (mutable_obj_clone): `Kernel#clone` should not copy
  FL_USER* flags because they are copied unexpectedly.
  Unexpected copy will break internal data consistency.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@63912 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 object.c                |  2 --
 test/ruby/test_clone.rb | 35 +++++++++++++++++++++++++++++++++++
 2 files changed, 35 insertions(+), 2 deletions(-)

diff --git a/object.c b/object.c
index 036e07b64f..9492abfac9 100644
--- a/object.c
+++ b/object.c
@@ -448,8 +448,6 @@ mutable_obj_clone(VALUE obj, int kwfreeze)
     VALUE clone, singleton;
 
     clone = rb_obj_alloc(rb_obj_class(obj));
-    RBASIC(clone)->flags &= (FL_TAINT|FL_PROMOTED0|FL_PROMOTED1);
-    RBASIC(clone)->flags |= RBASIC(obj)->flags & ~(FL_PROMOTED0|FL_PROMOTED1|FL_FREEZE|FL_FINALIZE);
 
     singleton = rb_singleton_class_clone_and_attach(obj, clone);
     RBASIC_SET_CLASS(clone, singleton);
diff --git a/test/ruby/test_clone.rb b/test/ruby/test_clone.rb
index 93ef438461..321feb07c7 100644
--- a/test/ruby/test_clone.rb
+++ b/test/ruby/test_clone.rb
@@ -26,4 +26,39 @@ class TestClone < Test::Unit::TestCase
 
     assert_equal([M003, M002, M001], M003.ancestors)
   end
+
+  def test_user_flags
+    assert_separately([], <<-EOS)
+      #
+      class Array
+        undef initialize_copy
+        def initialize_copy(*); end
+      end
+      x = [1, 2, 3].clone
+      assert_equal [], x, '[Bug #14847]'
+    EOS
+
+    assert_separately([], <<-EOS)
+      #
+      class Array
+        undef initialize_copy
+        def initialize_copy(*); end
+      end
+      x = [1,2,3,4,5,6,7][1..-2].clone
+      x.push(1,1,1,1,1)
+      assert_equal [1, 1, 1, 1, 1], x, '[Bug #14847]'
+    EOS
+
+    assert_separately([], <<-EOS)
+      #
+      class Hash
+        undef initialize_copy
+        def initialize_copy(*); end
+      end
+      h = {}
+      h.default_proc = proc { raise }
+      h = h.clone
+      assert_equal nil, h[:not_exist], '[Bug #14847]'
+    EOS
+  end
 end