From: "zenspider (Ryan Davis)" <redmine@...>
Date: 2012-12-29T13:35:21+09:00
Subject: [ruby-core:51180] [ruby-trunk - Bug #7564] r38175 introduces incompatibility


Issue #7564 has been updated by zenspider (Ryan Davis).


I still think this is a bug, as shown by needing a respond_to? that does nothing more than call super:

class Sexp < Array
  def inspect
    "s(#{map(&:inspect).join ', '})"
  end

  def respond_to? meth
    super
  end if ENV["WHY_DO_I_NEED_THIS"]

  def method_missing meth, delete = false
    raise "shouldn't be here: #{meth.inspect}"
  end
end

def s *args
  Sexp.new args
end

p Marshal.load Marshal.dump s(1, 2, 3)
puts

# % WHY_DO_I_NEED_THIS=1 ruby20 trunk_bug.rb && ruby20 trunk_bug.rb
# s(1, 2, 3)
#
# trunk_bug.rb:11:in `method_missing': shouldn't be here: :marshal_dump (RuntimeError)
#       from trunk_bug.rb:19:in `dump'
#       from trunk_bug.rb:19:in `<main>'

----------------------------------------
Bug #7564: r38175 introduces incompatibility
https://bugs.ruby-lang.org/issues/7564#change-35131

Author: tenderlovemaking (Aaron Patterson)
Status: Rejected
Priority: Normal
Assignee: mame (Yusuke Endoh)
Category: core
Target version: 2.0.0
ruby -v: ruby 2.0.0dev (2012-12-15 trunk 38381) [x86_64-darwin12.2.1]


r38175 introduces incompatibility with 1.9.3.  Before r38175, when looking for _dump, Marshal would not call method_missing.  Now marshal calls method_missing when trying to dump.

The following example exits with no error on 1.9.3, but on trunk it raises an exception (_dump() must return string (TypeError)):

class TR
  def initialize calls = []
    @calls = calls
  end

  def method_missing name, *args
    @calls << [name, args]
  end
end

Marshal.dump TR.new

I've attached a test case.


-- 
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