  def test_from_bad_octal
    test_cases = [
      "00000006,44\000", # bogus character
      "00000006789\000", # non-octal digit
      "+0000001234\000", # positive sign
      "-0000001000\000", # negative sign
      "0x000123abc\000", # radix prefix
    ]

    test_cases.each do |val|
      header_s = @tar_header.to_s
      # overwrite the size field
      header_s[124, 12] = val
      io = TempIO.new header_s
      assert_raises ArgumentError do
        new_header = Gem::Package::TarHeader.from io
      end
    end
  end
The program contains an iteration or loop with an exit condition that cannot be reached, i.e., an infinite loop.