[ruby-core:51369] [ruby-trunk - Bug #7564] r38175 introduces incompatibility

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


=begin
This seems highly inconsistent to me. Specifically, MM + RT is the only working solution, but RT implementation is entirely meaningless. It doesn't make sense to me that I need a method table entry that does nothing but super. That should be the same as not existing in the method table.

 ##
 # Notes:
 #
 # Runtime        = Passes        Failures
 # ---------------------------------------------------------------------------
 # (none)         =             | 1.8 1.9 2.0 fails #blah (expected)
 # MM             = 1.8 1.9     | 2.0 raises w/ marshal_dump
 # MM + RT        = 1.8 1.9 2.0 |
 # MM +      RTM  = 1.8 1.9     | 2.0 raises w/ marshal_dump (doesn't use RTM)
 # MM + RT + RTM  = 1.8 1.9 2.0 |
 # MM +      ARTM = 1.8         | 1.9 SSE, 2.0 raises
 # MM + RT + ARTM = 1.8         | 1.9 SSE, 2.0 SSE (SystemStackError)
 #      RT        =             | 1.8 1.9 2.0 fails #blah (expected)
 #           RTM  =             | 1.8 1.9 2.0 fails #blah (expected)
 #           ARTM =             | 1.8 2.0 fails #blah (expected), 1.9 SSE
 
  class Sexp < Array
    def inspect
      "s(#{map(&:inspect).join ', '})"
    end

    def method_missing meth, delete = false
      x = nil
      return x if x = find { |o| Sexp === o && o.first == meth }
      raise "shouldn't be here: #{inspect}.#{meth}"
    end if ENV["MM"]

    def respond_to? meth, private = false
      p :respond_to? => meth if ENV["V"]
      super
    end if ENV["RT"]

    def respond_to_missing? meth, private = false
      p :respond_to_missing? => meth if ENV["V"]
      super
    end if ENV["RTM"]

    alias respond_to_missing? respond_to? if ENV["ARTM"]
  end

  def s *args
    Sexp.new args
  end

  END { puts }
  p Marshal.load Marshal.dump s(1, 2, 3)
  p s(1, 2, s(:blah)).blah
 
=end

----------------------------------------
Bug #7564: r38175 introduces incompatibility
https://bugs.ruby-lang.org/issues/7564#change-35337

Author: tenderlovemaking (Aaron Patterson)
Status: Open
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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