From: "tenderlovemaking (Aaron Patterson)" <aaron@...>
Date: 2012-08-21T02:41:18+09:00
Subject: [ruby-core:47252] [ruby-trunk - Bug #6867] super in a Mutex#synchronize block


Issue #6867 has been updated by tenderlovemaking (Aaron Patterson).

File fix.patch added

I'm hitting this bug in the Rails tests too.  It does not need to be a synchronize block.  Any method that yields will cause this error:

    class A; def self.yielder; yield; end end
    
    class X
      def self.hello; 'hi'; end
    end
    
    class Y < X
      def self.hello; A.yielder { super() }; end
    end
    
    Y.hello

I've attached a patch with a test and fix.  It seems that the loop that walks up the control frames would stop even though there is a valid recipient for that method further up the stack.  I'm not incredibly pleased with my patch because it has to do a `kind_of` for each object as it walks up, but it does fix this bug.

Shugo - do you have a better fix for this, or may I apply this patch?

Thanks.
----------------------------------------
Bug #6867: super in a Mutex#synchronize block
https://bugs.ruby-lang.org/issues/6867#change-28945

Author: Eregon (Benoit Daloze)
Status: Open
Priority: Normal
Assignee: shugo (Shugo Maeda)
Category: core
Target version: 2.0.0
ruby -v: ruby 2.0.0dev (2012-08-14 trunk 36700) [x86_64-darwin10.8.0]


The following code:

require 'thread'

class Parent
  def meth
  end
end

class Child < Parent
  def meth
    Mutex.new.synchronize do
      super
    end
  end
end

Child.new.meth

raises

bug_super.rb:13:in `block in meth': can't find the method for super, which may be called in an orphan block (NoMethodError)
	from <internal:prelude>:10:in `synchronize'
	from bug_super.rb:12:in `meth'
	from bug_super.rb:18:in `<main>'

I met the bug with the listen gem: https://github.com/guard/listen/blob/master/lib/listen/adapters/darwin.rb#L22-25 .


-- 
http://bugs.ruby-lang.org/