Fix compiler warning about non-exhaustive match

[ashawley]

Specific warning looks like this:

src/test/scala/scala/xml/ReuseNodesTest.scala:86: match may not be exhaustive.
It would fail on the following inputs: (List(_), Nil), (Nil, List(_))
    (original.toList,transformed.toList) match {
    ^
one warning found

Seems like the method could be rewritten to just use zip and foreach. Could someone review to make sure the assertion still works, though? I wasn't sure how to break scala.xml.transform.BasicTransformer to verify.

[biswanaths]

Face Palm. Big thanks for correcting my spell mistakes.

[ashawley]

@biswanaths Would it be possible to write a unit test that verifies that I didn't introduce a bug, and that I preserved the fix in in #59? Seems like a unit test that uses a counter to count the number of times a function was called, as was shown in https://issues.scala-lang.org/browse/SI-4528 could do that?

[biswanaths]

Sure @ashawley, let me look into writing the mentioned unit test. The counter validation will definitely strengthen validation any fix, pointing linear time complexity.

[biswanaths]

Is there a way to write a count test for the code, without modifying the existing code ? I was thinking of inheriting and overriding the transform ( https://github.com/scala/scala-xml/blob/master/src/main/scala/scala/xml/transform/BasicTransformer.scala#L34) + plus incrementing the state in the derived. Any other ways, people can think of ?

[ashawley]

@biswanaths Yes, using a var counter seems appropriate to me.

[biswanaths]

Ok, will submit a pull request with that.

[ashawley]

@biswanaths I've added one for you. When you've verified the new unit test and merged it, I will rebase and push this PR so the Travis checks can run again.

[ashawley]

@biswanaths Thanks! After you merged, I've rebased and re-pushed this branch. Looks like the checks still passed.

[biswanaths]

@ashawley , this looks good to me. Should we merge this in ?

[ashawley]

@biswanaths Yes, it is ready to go. It has the latest commits from master.

I think it is worth merging. It would be nice to get rid of the warnings from the build output in SBT.

[biswanaths]

Thanks @ashawley . Sorry that I missed it for long time.