NPE in IR running TestIO#test_readline_limit_0

[headius]

Not sure what's up here and have done no investigation. This test is normally excluded.

TestIO#test_readlines_limit_0 = IRBreakJump.java:34:in `create': java.lang.NullPointerException
    from IRRuntimeHelpers.java:143:in `initiateBreak'
    from Interpreter.java:443:in `processReturnOp'
    from Interpreter.java:608:in `interpret'
    from Interpreter.java:680:in `INTERPRET_BLOCK'
    from InterpretedIRBlockBody.java:39:in `commonYieldPath'
    from IRBlockBody.java:133:in `doYield'
    from BlockBody.java:78:in `yield'
    from Block.java:143:in `yield'
    from RubyArray.java:1619:in `reverseEach'
    from RubyArray.java:1628:in `reverse_each'
    from RubyArray$INVOKER$i$0$0$reverse_each.gen:-1:in `call'
    from JavaMethod.java:458:in `call'
    from CachingCallSite.java:79:in `callBlock'
    from CachingCallSite.java:85:in `call'
    from CallBase.java:394:in `interpret'
    from Interpreter.java:376:in `processCall'
    from Interpreter.java:605:in `interpret'
    from Interpreter.java:697:in `INTERPRET_METHOD'
...

[headius]

Ping @subbuss @enebo

[enebo]

Just checked this against 1.7.13 -X-C and we OOM. Weird that this manifests as NPE so we might be catching something somewhere we shouldn't but this test is uncovering an error in our Java bits of IO so I don't know how big of a deal this is:

./bin/jruby -X-C ../jruby/snippets/ir3.rb
Run options: 

# Running tests:

E

Finished tests in 7.920000s, 0.1263 tests/s, 0.0000 assertions/s.

  1) Error:
test_foo(TestIO):
Java::JavaLang::OutOfMemoryError: Java heap space
    org.jruby.RubyArray.realloc(RubyArray.java:366)
    org.jruby.RubyArray.append(RubyArray.java:1144)
    org.jruby.RubyIO.readlinesCommon(RubyIO.java:3562)
    org.jruby.RubyIO.readlines19(RubyIO.java:3550)
    org.jruby.RubyIO$INVOKER$i$0$2$readlines19.call(RubyIO$INVOKER$i$0$2$readlines19.gen)
    org.jruby.internal.runtime.methods.JavaMethod$JavaMethodN.call(JavaMethod.java:665)
    org.jruby.internal.runtime.methods.DynamicMethod.call(DynamicMethod.java:206)
    org.jruby.runtime.callsite.CachingCallSite.cacheAndCall(CachingCallSite.java:326)
    org.jruby.runtime.callsite.CachingCallSite.call(CachingCallSite.java:170)
    org.jruby.ast.CallOneArgNode.interpret(CallOneArgNode.java:57)
    org.jruby.ast.NewlineNode.interpret(NewlineNode.java:105)
    org.jruby.evaluator.ASTInterpreter.INTERPRET_BLOCK(ASTInterpreter.java:112)
    org.jruby.runtime.Interpreted19Block.evalBlockBody(Interpreted19Block.java:206)
    org.jruby.runtime.Interpreted19Block.yield(Interpreted19Block.java:157)
    org.jruby.runtime.Block.yield(Block.java:142)
    org.jruby.RubyIO.open(RubyIO.java:1181)
    org.jruby.RubyKernel.open19(RubyKernel.java:349)
    org.jruby.RubyKernel$INVOKER$s$0$3$open19.call(RubyKernel$INVOKER$s$0$3$open19.gen)
    org.jruby.internal.runtime.methods.DynamicMethod.call(DynamicMethod.java:218)
    org.jruby.runtime.callsite.CachingCallSite.cacheAndCall(CachingCallSite.java:356)
    org.jruby.runtime.callsite.CachingCallSite.callBlock(CachingCallSite.java:213)
    org.jruby.runtime.callsite.CachingCallSite.callIter(CachingCallSite.java:222)
    org.jruby.ast.FCallTwoArgBlockNode.interpret(FCallTwoArgBlockNode.java:34)
    org.jruby.ast.NewlineNode.interpret(NewlineNode.java:105)
    org.jruby.evaluator.ASTInterpreter.INTERPRET_BLOCK(ASTInterpreter.java:112)
    org.jruby.runtime.Interpreted19Block.evalBlockBody(Interpreted19Block.java:206)
    org.jruby.runtime.Interpreted19Block.yield(Interpreted19Block.java:157)
    org.jruby.runtime.Interpreted19Block.yieldSpecific(Interpreted19Block.java:135)
    org.jruby.runtime.Block.yieldSpecific(Block.java:120)
    org.jruby.ast.YieldOneNode.interpret(YieldOneNode.java:35)
    org.jruby.ast.NewlineNode.interpret(NewlineNode.java:105)
    org.jruby.ast.EnsureNode.interpret(EnsureNode.java:96)

1 tests, 0 assertions, 0 failures, 1 errors, 0 skips

[headius]

This no longer NPEs on master. It doesn't pass, but yeah.