From: Jean-Christophe Le Lann <jean-christophe.lelann@...>
Date: 2010-11-07T01:08:03+09:00
Subject: random bug in the & (set intersection) operator in Arrays

Hi

I think I have discovered a random bug in the & (set intersection) 
operator in Arrays.

It statistically appeared 37 times out of 200 executions of my program.

on version ruby 1.9.1p376 (2009-12-07 revision 26041) [i686-linux]
on version ruby 1.9.2p0 (2010-08-18 revision 29036) [i686-linux]

I cannot deliver this full program (a source to source compiler) but 
here is a example :

array1 = [#<While:0x8a15808>,
  #<Say:0x8b0c2c0 @str="2_1a">,
  #<Say:0x8b0c25c @str="2_1b">,
  #<If:0x8b0c1d0 @body=[#<Say:0x8b0c054 @str="2_1c">], @cond=true>]
========================================
array2 = [#<Say:0x8b0c2c0 @str="2_1a">,
  #<Say:0x8b0c25c @str="2_1b">,
  #<If:0x8b0c1d0 @body=[#<Say:0x8b0c054 @str="2_1c">], @cond=true>,
  #<While:0x8b0c02c,
  #<If:0x8b0bb2c @body=[#<Say:0x8b0baa0 @str="2_3">], @cond=true>,
  #<Else:0x8b0ba78 @body=[#<Say:0x8b0b94c @str="2_3">]>]
========================================
array1 & array2 sometimes gives things like :

[#<While:0x8a15808 >,
  #<Say:0x8b0c2c0 @str="2_1a">,
  #<Say:0x8b0c25c @str="2_1b">,
  #<If:0x8b0c1d0 @body=[#<Say:0x8b0c054 @str="2_1c">], @cond=true>]

while the expected result is

[#<Say:0x8b0c2c0 @str="2_1a">,
  #<Say:0x8b0c25c @str="2_1b">,
  #<If:0x8b0c1d0 @body=[#<Say:0x8b0c054 @str="2_1c">], @cond=true>]

How can I report that ? Thx
JCLL
(ps : using Set instead of Array, this works perfectly)