So many test failures. What is going on?
Which basically blocks the use of Rails 4.2 with JRuby, at least if you are concerned about working html sanitization.
Most if not all of the problems seem to be Nokogiri-Java problems where it behaves different from C-Nokogiri. I started working on some Nokogiri test cases that reproduce what loofah does, see sparklemotion/nokogiri#1318, sparklemotion/nokogiri#1319 and sparklemotion/nokogiri#1320. At least the last one looks more like a Xalan-J bug...
I have confirmed sparklemotion/nokogiri#1318 reduces jruby errors.