JRuby encode bug examples

gistfile1.rb

=begin
Here are some base64 encoded sequences of bytes that cause JRuby to hang:

7bWdZw==
7by/Vg==
DO27qA==
7bu1Lg==

UhbtqbHF04o=
bjlSh+2guiM=
NOrtppL+zQA=
7b27A0BGi5w=

4fGnt05Uqe2jqI7RKi664g==
7aa4Ne2wUuJb9ozCry1aqw==
gzEH7bWg2hvaUVohitrNRA==
meXI23O/mZrAX8u27bG3OQ==
=end

# Here is the script I used to find them.

require 'base64'

NUM_BYTES = 16

rand = Random.new
while true
  data = rand.bytes(NUM_BYTES)
  data.force_encoding("UTF-8")

  puts "data=#{Base64.encode64(data)}"

  puts "Before calling encode: data.length=#{data.length}"

  data = data.encode("UTF-16", :undef => :replace, :invalid => :replace, :replace => '')
  puts "After calling encode: data.length=#{data.length}"

  puts "\n"
end