Valid xpath crashes the lib with NPE

Example xml snippet:

<tbody>
    <tr>
        <td>NoLuck</td>
        <td>
            <span>NoHit</span>
        </td>
    </tr>
    <tr>
        <td>whatever</td>
        <td>
            <span>ShouldHit</span>
        </td>
    </tr>
    <tr>
        <td>Again</td>
        <td>
            <span>NoHit</span>
        </td>
    </tr>
</tbody>

XPath:
//table/tbody/tr[contains(td,'whatever']/td/span/text()

It should return: ShouldHit as verified with w3cSchool online tool.
Instead it throws NullPointerException:

Exception in thread "main" java.lang.NullPointerException
at us.codecraft.xsoup.xevaluator.CombiningEvaluator$And.matches(CombiningEvaluator.java:53)
at us.codecraft.xsoup.xevaluator.CombiningEvaluator$And.matches(CombiningEvaluator.java:53)
at us.codecraft.xsoup.xevaluator.StructuralEvaluator$ImmediateParent.matches(StructuralEvaluator.java:84)
at us.codecraft.xsoup.xevaluator.CombiningEvaluator$And.matches(CombiningEvaluator.java:53)
at us.codecraft.xsoup.xevaluator.StructuralEvaluator$ImmediateParent.matches(StructuralEvaluator.java:84)
at us.codecraft.xsoup.xevaluator.CombiningEvaluator$And.matches(CombiningEvaluator.java:53)
at org.jsoup.select.Collector$Accumulator.head(Collector.java:42)
at org.jsoup.select.NodeTraversor.traverse(NodeTraversor.java:31)
at org.jsoup.select.Collector.collect(Collector.java:24)
at us.codecraft.xsoup.xevaluator.DefaultXPathEvaluator.evaluate(DefaultXPathEvaluator.java:29)

Reproduce the supplied XML and XPath example, then start with CombiningEvaluator.java:53 and follow the stack through StructuralEvaluator.java:84 and DefaultXPathEvaluator.java:29. The work is done when the expression returns “ShouldHit” without throwing a NullPointerException.