merge revision(s) 4b36a597f48c857aa5eb9ed80fec0d02f6284646: [Backport #17519]

	Fix setting method visibility for a refinement without an origin
	 class

	If a class has been refined but does not have an origin class,
	there is a single method entry marked with VM_METHOD_TYPE_REFINED,
	but it contains the original method entry.  If the original method
	entry is present, we shouldn't skip the method when searching even
	when skipping refined methods.

	Fixes [Bug #17519]
	---
	 test/ruby/test_module.rb | 110 ++++++++++++++++++++++++++++++++++++++++++++++-
	 vm_method.c              |   3 +-
	 2 files changed, 111 insertions(+), 2 deletions(-)

1 files changed, 109 insertions, 1 deletions

diff --git a/test/ruby/test_module.rb b/test/ruby/test_module.rb
index 254dc51b9b..5db6732fee 100644
--- a/test/ruby/test_module.rb
+++ b/test/ruby/test_module.rb
@@ -2237,7 +2237,7 @@ class TestModule < Test::Unit::TestCase
     assert_equal(0, 1 / 2)
   end
 
-  def test_visibility_after_refine_and_visibility_change
+  def test_visibility_after_refine_and_visibility_change_with_origin_class
     m = Module.new
     c = Class.new do
       def x; :x end
@@ -2260,6 +2260,114 @@ class TestModule < Test::Unit::TestCase
     assert_equal(:x, o2.public_send(:x))
   end
 
+  def test_visibility_after_multiple_refine_and_visibility_change_with_origin_class
+    m = Module.new
+    c = Class.new do
+      def x; :x end
+    end
+    c.prepend(m)
+    Module.new do
+      refine c do
+        def x; :y end
+      end
+    end
+    Module.new do
+      refine c do
+        def x; :z end
+      end
+    end
+
+    o1 = c.new
+    o2 = c.new
+    assert_equal(:x, o1.public_send(:x))
+    assert_equal(:x, o2.public_send(:x))
+    o1.singleton_class.send(:private, :x)
+    o2.singleton_class.send(:public, :x)
+
+    assert_raise(NoMethodError) { o1.public_send(:x) }
+    assert_equal(:x, o2.public_send(:x))
+  end
+
+  def test_visibility_after_refine_and_visibility_change_without_origin_class
+    c = Class.new do
+      def x; :x end
+    end
+    Module.new do
+      refine c do
+        def x; :y end
+      end
+    end
+    o1 = c.new
+    o2 = c.new
+    o1.singleton_class.send(:private, :x)
+    o2.singleton_class.send(:public, :x)
+    assert_raise(NoMethodError) { o1.public_send(:x) }
+    assert_equal(:x, o2.public_send(:x))
+  end
+
+  def test_visibility_after_multiple_refine_and_visibility_change_without_origin_class
+    c = Class.new do
+      def x; :x end
+    end
+    Module.new do
+      refine c do
+        def x; :y end
+      end
+    end
+    Module.new do
+      refine c do
+        def x; :z end
+      end
+    end
+    o1 = c.new
+    o2 = c.new
+    o1.singleton_class.send(:private, :x)
+    o2.singleton_class.send(:public, :x)
+    assert_raise(NoMethodError) { o1.public_send(:x) }
+    assert_equal(:x, o2.public_send(:x))
+  end
+
+  def test_visibility_after_refine_and_visibility_change_with_superclass
+    c = Class.new do
+      def x; :x end
+    end
+    sc = Class.new(c)
+    Module.new do
+      refine sc do
+        def x; :y end
+      end
+    end
+    o1 = sc.new
+    o2 = sc.new
+    o1.singleton_class.send(:private, :x)
+    o2.singleton_class.send(:public, :x)
+    assert_raise(NoMethodError) { o1.public_send(:x) }
+    assert_equal(:x, o2.public_send(:x))
+  end
+
+  def test_visibility_after_multiple_refine_and_visibility_change_with_superclass
+    c = Class.new do
+      def x; :x end
+    end
+    sc = Class.new(c)
+    Module.new do
+      refine sc do
+        def x; :y end
+      end
+    end
+    Module.new do
+      refine sc do
+        def x; :z end
+      end
+    end
+    o1 = sc.new
+    o2 = sc.new
+    o1.singleton_class.send(:private, :x)
+    o2.singleton_class.send(:public, :x)
+    assert_raise(NoMethodError) { o1.public_send(:x) }
+    assert_equal(:x, o2.public_send(:x))
+  end
+
   def test_prepend_visibility
     bug8005 = '[ruby-core:53106] [Bug #8005]'
     c = Class.new do