[scala-bts] #2674: NPE in scala.xml.MetaData#containedIn1 Stemming from equals

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Reporter: djspiewak | Owner: scala-xml_team
Type: defect | Status: new
Priority: normal | Component: XML support
Keywords: |
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Consider the following snippet:

{{{
.child contains
}}}

Obviously, this should return '''true'''. However, the actual result is
the following NullPointerException:

{{{
java.lang.NullPointerException
at scala.xml.MetaData.containedIn1(MetaData.scala:140)
at scala.xml.MetaData.containedIn1(MetaData.scala:140)
at scala.xml.MetaData.containedIn1(MetaData.scala:140)
at scala.xml.MetaData.containedIn1(MetaData.scala:140)
at scala.xml.MetaData.equals(MetaData.scala:166)
at scala.xml.Node.equals(Node.scala:136)
at scala.runtime.BoxesRunTime.equals(Unknown Source)
at scala.Seq$$anonfun$contains$1.apply(Seq.scala:396)
at scala.Seq$$anonfun$contains$1.apply(Seq.scala:396)
at scala.Iterator$class.exists(Iterator.scala:440)
at
scala.collection.mutable.ResizableArray$$anon$1.exists(ResizableArray.scala:66)
at scala.Iterable$class.exists(Iterable.scala:276)
at
scala.collection.mutable.ArrayBuffer.exists(ArrayBuffer.scala:26)
at scala.Seq$class.contains(Seq.scala:396)
at
scala.collection.mutable.ArrayBuffer.contains(ArrayBuffer.scala:26)
at line19$object$$iw$$iw$$iw$.liftedTree1$1(:7)
at line19$object$$iw$$iw$$iw$.(:7)
at line19$object$$iw$$iw$$iw$.()
at RequestResult$line19$object$.(:3)
at RequestResult$line19$object$.()
at RequestResult$line19$object.result()
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at
scala.tools.nsc.Interpreter$Request.loadAndRun(Interpreter.scala:889)
at scala.tools.nsc.Interpreter.interpret(Interpreter.scala:508)
at scala.tools.nsc.Interpreter.interpret(Interpreter.scala:494)
at
scala.tools.nsc.InterpreterLoop.interpretStartingWith(InterpreterLoop.scala:242)
at
scala.tools.nsc.InterpreterLoop.command(InterpreterLoop.scala:230)
at scala.tools.nsc.InterpreterLoop.repl(InterpreterLoop.scala:142)
at scala.tools.nsc.InterpreterLoop.main(InterpreterLoop.scala:298)
at
scala.tools.nsc.MainGenericRunner$.main(MainGenericRunner.scala:141)
at scala.tools.nsc.MainGenericRunner.main(MainGenericRunner.scala)
}}}

This appears to stem from the following method in MetaData:

{{{
def containedIn1(m: MetaData): Boolean =
m.equals1(this) || containedIn1(m.next)
}}}

I suspect that this should be changed to the following:

{{{
def containedIn1(m: MetaData): Boolean =
m.equals1(this) || (m.hasNext && containedIn1(m.next))
}}}