Hey guys,
just upgraded jruby to 1.7.13 and my less compiler, which uses therubyrhino for its js execution started acting up.

More to the point org.jruby.java.proxies.ArrayJavaProxy.to_a seems to throw an NPE, although looking at the source, I do not see at a glance what the issue could be.

I posted the issue at therubyrhino project as well: rubyjs/therubyrhino#31

2014-08-06 12:30:00 +0200: Rack app error: java.lang.NullPointerException
org.jruby.java.proxies.ArrayJavaProxy.to_a(org/jruby/java/proxies/ArrayJavaProxy.java:145)
RUBY.method_missing(/Users/slawo/.rvm/gems/jruby-1.7.13/gems/therubyrhino-2.0.3/lib/rhino/rhino_ext.rb:115)
org.mozilla.javascript.optimizer.OptRuntime.callName(org/mozilla/javascript/optimizer/OptRuntime.java:63)
org.mozilla.javascript.gen._Users_slawo__rvm_gems_jruby_1_7_13_gems_less_2_5_0_lib_less_js_lib_less_parser_js_2._c_anonymous_31(/Users/slawo/.rvm/gems/jruby-1.7.13/gems/less-2.5.0/lib/less/js/lib/less/parser.js:669)

The error does not happen with jruby 1.7.11/12. It happens reliably with 1.7.13.
Is there any change in semantics/arguments?

I am running on Oracle Java on Mac OSX:

java version "1.7.0_55"
Java(TM) SE Runtime Environment (build 1.7.0_55-b13)
Java HotSpot(TM) 64-Bit Server VM (build 24.55-b03, mixed mode)