>> a = 'ABC'.encode('UTF-16LE')
=> "ABC"
>> b = 'ABC'.encode('UTF-16LE')
=> "ABC"
>> b.casecmp(a)

Java::JavaLang::ArrayIndexOutOfBoundsException: -1
    from org.jruby.RubyString.multiByteCasecmp(RubyString.java:1661)
    from org.jruby.RubyString.casecmp19(RubyString.java:1636)
    from org.jruby.RubyString$INVOKER$i$1$0$casecmp19.call(RubyString$INVOKER$i$1$0$casecmp19.gen)
    from org.jruby.runtime.callsite.CachingCallSite.cacheAndCall(CachingCallSite.java:326)
    from org.jruby.runtime.callsite.CachingCallSite.call(CachingCallSite.java:170)
    from org.jruby.ast.CallOneArgNode.interpret(CallOneArgNode.java:57)
    from org.jruby.ast.NewlineNode.interpret(NewlineNode.java:105)
    from org.jruby.ast.RootNode.interpret(RootNode.java:129)
    from org.jruby.evaluator.ASTInterpreter.INTERPRET_EVAL(ASTInterpreter.java:95)
    from org.jruby.evaluator.ASTInterpreter.evalWithBinding(ASTInterpreter.java:184)
    from org.jruby.RubyKernel.evalCommon(RubyKernel.java:1156)
    from org.jruby.RubyKernel.eval19(RubyKernel.java:1119)
    from org.jruby.RubyKernel$INVOKER$s$0$3$eval19.call(RubyKernel$INVOKER$s$0$3$eval19.gen)
    from org.jruby.internal.runtime.methods.DynamicMethod.call(DynamicMethod.java:180)
    from org.jruby.runtime.callsite.CachingCallSite.call(CachingCallSite.java:70)
    from org.jruby.ast.FCallManyArgsNode.interpret(FCallManyArgsNode.java:60)
... 114 levels...
    from org.jruby.ast.BlockNode.interpret(BlockNode.java:71)
    from org.jruby.evaluator.ASTInterpreter.INTERPRET_METHOD(ASTInterpreter.java:74)
    from org.jruby.internal.runtime.methods.InterpretedMethod.call(InterpretedMethod.java:182)
    from org.jruby.internal.runtime.methods.DefaultMethod.call(DefaultMethod.java:198)
    from org.jruby.runtime.callsite.CachingCallSite.cacheAndCall(CachingCallSite.java:326)
    from org.jruby.runtime.callsite.CachingCallSite.call(CachingCallSite.java:170)
    from from bin.irb.__file__(bin/irb:13)
    from bin.irb.load(bin/irb)
    from org.jruby.Ruby.runScript(Ruby.java:811)
    from org.jruby.Ruby.runScript(Ruby.java:804)
    from org.jruby.Ruby.runNormally(Ruby.java:673)
    from org.jruby.Ruby.runFromMain(Ruby.java:522)
    from org.jruby.Main.doRunFromMain(Main.java:395)
    from org.jruby.Main.internalRun(Main.java:290)
    from org.jruby.Main.run(Main.java:217)
    from org.jruby.Main.main(Main.java:197)