Fix Kernel#singleton_method with Module#Prepend

* proc.c (rb_obj_singleton_method): search the method entry from
  the origin class, for fix prepended modules.  [Bug #14658]

From: Vasiliy Ermolovich <younash@gmail.com>

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@63067 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 10 insertions, 0 deletions

diff --git a/test/ruby/test_method.rb b/test/ruby/test_method.rb
index 0ef913fd78..67c24a8fd8 100644
--- a/test/ruby/test_method.rb
+++ b/test/ruby/test_method.rb
@@ -782,6 +782,16 @@ class TestMethod < Test::Unit::TestCase
     assert_equal(:bar, m.call, feature8391)
   end
 
+  def test_singleton_method_prepend
+    bug14658 = '[Bug #14658]'
+    c1 = Class.new
+    o = c1.new
+    def o.bar; :bar; end
+    class << o; prepend Module.new; end
+    m = assert_nothing_raised(NameError, bug14658) {o.singleton_method(:bar)}
+    assert_equal(:bar, m.call, bug14658)
+  end
+
   Feature9783 = '[ruby-core:62212] [Feature #9783]'
 
   def assert_curry_three_args(m)