Test to illustrate that JRuby on windows doesn't correctly transfer binmode to a duplicate

dup-test.rb

require 'test/unit'
include Test::Unit::Assertions

EXPECTED = "\211PNG\r\n\032\n"
File.open('test.dmp', 'wb') do |f|
  f.write(EXPECTED)
end

o = File.new('test.dmp', 'rb')
assert_equal EXPECTED, o.read(8), "not in binmode" # works
o.seek(0,0)
od = o.dup
assert_equal EXPECTED, od.read(8), "dup not in binmode" # fails