From: Nobuyoshi Nakada <redmine@...>
Date: 2009-12-02T17:00:03+09:00
Subject: [ruby-core:27000] [Bug #2420] super call may use wrong receiver object

Bug #2420: super call may use wrong receiver object
http://redmine.ruby-lang.org/issues/show/2420

Author: Nobuyoshi Nakada
Status: Open, Priority: Normal
Assigned to: Nobuyoshi Nakada, Category: core
ruby -v: ruby 1.9.2dev (2009-12-01 trunk 25970) [i386-darwin9.0]

The code below prints:
C
main
Object::m

which means that the super calls the instance method B#m on a receiver that is not an instance of B. It's not what makes the super call to pick the main object as a receiver in this case. I would expect it to use the "self" object that the block captures, i.e. the class object C, and thus an exception "no superclass method `m' (NoMethodError)" should be raised.

class B
  def m
    p self
    puts self.class.to_s + '::m'
  end
end

class C < B
  q = Proc.new do
    p self
    super()
  end
  
  mq = define_method :m, &q
  
  mq.call
end


BTW: The behavior is even worse in Ruby 1.9:
ruby 1.9.1p129 (2009-05-12 revision 23412) [i386-mswin32]
C
a.rb:11:in `==': wrong number of arguments(0 for 1) (ArgumentError)
        from a.rb:11:in `block in <class:C>'
        from a.rb:16:in `call'
        from a.rb:16:in `<class:C>'
        from a.rb:8:in `<main>'


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