reset cache before iterating

cee02d754d76563635c1db90d2ab6c01f8492470 resets pCMC and `me`
will be a invalidated and continuing the invalidated `me`,
it will break the data structure. This patch tris to clear
all methods of specified class before manipulating the `me`s.
[Issue #17417]

1 files changed, 26 insertions, 6 deletions

diff --git a/test/ruby/test_refinement.rb b/test/ruby/test_refinement.rb
index b27a176889..c364de46e4 100644
--- a/test/ruby/test_refinement.rb
+++ b/test/ruby/test_refinement.rb
@@ -2441,12 +2441,6 @@ class TestRefinement < Test::Unit::TestCase
     $VERBOSE = verbose_bak
   end
 
-  private
-
-  def eval_using(mod, s)
-    eval("using #{mod}; #{s}", Sandbox::BINDING)
-  end
-
   # [Bug #17386]
   def test_prepended_with_method_cache
     foo = Class.new do
@@ -2473,4 +2467,30 @@ class TestRefinement < Test::Unit::TestCase
     foo.prepend code
     assert_equal :Code, obj.foo
   end
+
+  # [Bug #17417]
+  def test_prepended_with_method_cache_17417
+    assert_normal_exit %q{
+      module M
+        def hoge; end
+      end
+
+      module R
+        refine Hash do
+          def except *args; end
+        end
+      end
+
+      h = {}
+      h.method(:except) # put it on pCMC
+      Hash.prepend(M)
+      h.method(:except)
+    }
+  end
+
+  private
+
+  def eval_using(mod, s)
+    eval("using #{mod}; #{s}", Sandbox::BINDING)
+  end
 end