Forum: Ruby-core nil.instance_eval pushes nil onto cref

Issue #2788 has been updated by shugo (Shugo Maeda).

Priority changed from Low to Normal

ko1 (Koichi Sasada) wrote:
> nobu has patach.

Does he have a Hebrew niqqud vowel sign?
Aside from the joke, why not apply the patch, Nobu?

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Bug #2788: nil.instance_eval pushes nil onto cref
https://bugs.ruby-lang.org/issues/2788#change-28672

Author: shugo (Shugo Maeda)
Status: Assigned
Priority: Normal
Assignee: nobu (Nobuyoshi Nakada)
Category: core
Target version: 2.0.0
ruby -v: ruby 1.9.2dev (2010-02-18 trunk 26704) [i686-linux]


=begin
 A singleton class definition of nil pushes NilClass onto cref.
 It is reasonable because NilClass has nil as the only instance.
 However, nil.instance_eval pushes nil onto cref, which means that 
method definitions are not permitted in that context.

   defiant:ruby$ ruby-trunk -ve 'class <<nil; def foo; puts "foo" end; 
end; nil.foo'
   ruby 1.9.2dev (2010-02-18 trunk 26704) [i686-linux]
   foo
   defiant:ruby$ ruby-trunk -ve 'nil.instance_eval {|i| def foo; puts 
"foo" end }; nil.foo'
   ruby 1.9.2dev (2010-02-18 trunk 26704) [i686-linux]
   -e:1:in `block in <main>': no class/module to add method (TypeError)
     from -e:1:in `instance_eval'
     from -e:1:in `<main>'

 The behavior is the same in Ruby 1.8.7.
 Is it intended or a bug?
=end

Hello,

In message "[ruby-core:47015] [ruby-trunk - Bug #2788] nil.instance_eval 
pushes nil onto cref"
    on Aug.06,2012 17:15:16, <redmine@ruby-lang.org> wrote:
> Aside from the joke, why not apply the patch, Nobu?

Wait until he drives his time machine.


Regards,