1 files changed, 49 insertions, 0 deletions
diff --git a/test/ruby/test_refinement.rb b/test/ruby/test_refinement.rb
index c364de46e4..b386c3a8d7 100644
--- a/test/ruby/test_refinement.rb
+++ b/test/ruby/test_refinement.rb
@@ -2488,6 +2488,55 @@ class TestRefinement < Test::Unit::TestCase
     }
   end
 
+  def test_defining_after_cached
+    klass = Class.new
+    refinement = Module.new { refine(klass) { def foo; end } }
+    klass.new.foo rescue nil # cache the refinement method entry
+    klass.define_method(:foo) { 42 }
+    assert_equal(42, klass.new.foo)
+  end
+
+  # [Bug #17806]
+  def test_two_refinements_for_prepended_class
+    assert_normal_exit %q{
+      module R1
+        refine Hash do
+          def foo; :r1; end
+        end
+      end
+
+      class Hash
+        prepend(Module.new)
+      end
+
+      class Hash
+        def foo; end
+      end
+
+      {}.method(:foo) # put it on pCMC
+
+      module R2
+        refine Hash do
+          def foo; :r2; end
+        end
+      end
+
+      {}.foo
+    }
+  end
+
+  # [Bug #17806]
+  def test_redefining_refined_for_prepended_class
+    klass = Class.new { def foo; end }
+    _refinement = Module.new do
+      refine(klass) { def foo; :refined; end }
+    end
+    klass.prepend(Module.new)
+    klass.new.foo # cache foo
+    klass.define_method(:foo) { :second }
+    assert_equal(:second, klass.new.foo)
+  end
+
   private
 
   def eval_using(mod, s)