Bug #12478: ruby2.2.5でオブジェクトに対して def_delegatorを行うとNoMethodError undefined method `method_defined?' が発生する。

• Status: Closed
• Assignee: -
• Target version: -
• ruby -v: 2.2.5
• Backport: 2.1: DONTNEED, 2.2: DONE, 2.3: DONE

[[e-mail] (keiichi ishioka)]

• 再現コード

  printer = String.new
  printer.extend SingleForwardable
  printer.def_delegator "STDOUT", :puts
  # NoMethodError: undefined method `method_defined?' for "":String
  

• 原因

• def_single_delegatorで "method_defined?"を行っていますが、

• Moduleクラスをmix-inしていないオブジェクトの場合NoMethodErrorになる。

• 回避方法案

  • Moduleが該当オブジェクトのclassに属していない場合,該当処理をスキップする

    ```diff
    --- /usr/local/.rbenv/versions/2.2.5/lib/ruby/2.2.0/forwardable.rb.org  2016-06-10 10:31:09.613979605 +0900
    +++ /usr/local/.rbenv/versions/2.2.5/lib/ruby/2.2.0/forwardable.rb      2016-06-10 10:35:06.452506085 +0900
    @@ -277,7 +277,7 @@
        accessor = accessor.to_s
        if method_defined?(accessor) || private_method_defined?(accessor)
          accessor = "#{accessor}()"
    -    end if
    +    end if self.class === Module
    
        line_no = __LINE__; str = %{
          def #{ali}(*args, &block)
    ```
    

[nobu (Nobuyoshi Nakada)]

• Description updated (diff)
• Backport changed from 2.1: UNKNOWN, 2.2: UNKNOWN, 2.3: UNKNOWN to 2.1: DONTNEED, 2.2: REQUIRED, 2.3: REQUIRED

[nobu (Nobuyoshi Nakada)]

• Status changed from Open to Closed

Applied in changeset r55366.

---

forwardable.rb: fix for non-module objects

• lib/forwardable.rb (Forwardable._delegator_method): extract
  method generator and deal with non-module objects.
  [ruby-dev:49656] [Bug #12478]

[nagachika (Tomoyuki Chikanaga)]

• Backport changed from 2.1: DONTNEED, 2.2: REQUIRED, 2.3: REQUIRED to 2.1: DONTNEED, 2.2: REQUIRED, 2.3: DONE

ruby_2_3 r57570 merged revision(s) 53383,55366.

[usa (Usaku NAKAMURA)]

• Backport changed from 2.1: DONTNEED, 2.2: REQUIRED, 2.3: DONE to 2.1: DONTNEED, 2.2: DONE, 2.3: DONE

ruby_2_2 r58085 merged revision(s) 53383,55366.