Handler is invoked event when path expression isn't matched

[kipz]

Reported by @cdupuis

03/21 02:03:22.667 ERROR [l:fcf5e813-cb0d-4c03-9f7b-8668b25353] c.a.r.r.i.o.EventHandlerInvoker - Failed event-handler-OpenedIssue of atomist-rugs:beta-default-handlers:0.13.0
com.atomist.rug.InvalidHandlerResultException: OpenedIssue EventHandler returned an invalid response (undefined) when handling /Issue()[/resolvedBy::Commit()/author::GitHubId()[/hasGithubIdentity::Person()/hasChatIdentity::ChatId()]?]?[/by::GitHubId()[/hasGithubIdentity::Person()/hasChatIdentity::ChatId()]?][/belongsTo::Repo()/channel::ChatChannel()]
at com.atomist.rug.runtime.js.JavaScriptEventHandler.handle(JavaScriptEventHandler.scala:67)
at com.atomist.rug.resolver.loader.ProvenanceAddingRugLoader$DecoratedEventHandler.handle(ProvenanceAddingRugLoader.java:549)
at com.atomist.rug.runner.invoke.operation.EventHandlerInvoker.lambda$invokeHandler$20(EventHandlerInvoker.java:58)
at java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1374)
at java.util.stream.ReferencePipeline$Head.forEach(ReferencePipeline.java:580)
at com.atomist.rug.runner.invoke.operation.EventHandlerInvoker.invokeHandler(EventHandlerInvoker.java:52)
at com.atomist.rug.runner.invoke.OperationsWrappingInvoker.invokeHandler(OperationsWrappingInvoker.java:51)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at com.atomist.rug.runner.invoke.OperationCoordinator.handleEvent(OperationCoordinator.java:113)
at com.atomist.rug.runner.service.EventHandlerDispatcher$$anonfun$invokeHandlers$1.apply(EventHandlerDispatcher.scala:69)
at com.atomist.rug.runner.service.EventHandlerDispatcher$$anonfun$invokeHandlers$1.apply(EventHandlerDispatcher.scala:69)
at scala.collection.immutable.List.foreach(List.scala:381)
at com.atomist.rug.runner.service.EventHandlerDispatcher.invokeHandlers(EventHandlerDispatcher.scala:69)
at com.atomist.rug.runner.service.EventHandlerDispatcher$$anonfun$poll$1$$anonfun$apply$mcV$sp$1.apply(EventHandlerDispatcher.scala:43)
at com.atomist.rug.runner.service.EventHandlerDispatcher$$anonfun$poll$1$$anonfun$apply$mcV$sp$1.apply(EventHandlerDispatcher.scala:42)
at com.atomist.kafka.Messa