Issue #11182 has been reported by Koichi Sasada.

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Bug #11182: Refinement with alias causes strange behavior
https://bugs.ruby-lang.org/issues/11182

* Author: Koichi Sasada
* Status: Open
* Priority: Normal
* Assignee: 
* ruby -v: 2.3dev
* Backport: 2.0.0: UNKNOWN, 2.1: UNKNOWN, 2.2: UNKNOWN
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The following script causes strange behavior.

```ruby
class C
  def foo
    p "C"
  end
end

module M
  refine C do
    def foo
      p "Refiend C"
    end
  end
end

class D < C
  alias bar foo
end

using M
D.new.bar
#=> t.rb:21:in `<main>': undefined method `bar' for #<D:0x29fbf58> (NoMethodError)
```

It seems strange.

Maybe (1) C#foo or (2) M#C#foo should be called. But I'm not sure which is suitable.

Previous versions:

```
ruby 2.0.0p606 (2014-11-28 revision 48636) [i386-mswin32_110]
t.rb:9: warning: Refinements are experimental, and the behavior may change in future versions of Ruby!
"C"

ruby 2.1.5p312 (2015-03-10 revision 49912) [i386-mswin32_110]
"C"
```




-- 
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