Issue #10885 has been updated by Tomoyuki Chikanaga.

Backport changed from 2.0.0: DONE, 2.1: REQUIRED, 2.2: DONE to 2.0.0: DONE,2.1: DONE, 2.2: DONE

Backported into `ruby_2_1` branch at r49995.

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Bug #10885: Segmentation fault when calling refined method in duplicate module
https://bugs.ruby-lang.org/issues/10885#change-51867

* Author: Kazuki Tsujimoto
* Status: Closed
* Priority: Normal
* Assignee: 
* ruby -v: ruby 2.3.0dev (2015-02-22) [x86_64-linux]
* Backport: 2.0.0: DONE, 2.1: DONE, 2.2: DONE
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以下のコードでSEGVします。
Moduleをdupする時にcrefをコピーしていますが、その中でnd_refinementsを設定していないのが原因です。

~~~ruby
module M
  refine BasicObject do
    def __id__
    end
  end

  class << self
    def m
      __id__
    end
  end
end

M.dup.m
~~~




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