public static  void main(String[] args) 
{
        TestRunner.run(XPathBugTest.class);
}

 public  void testMikeSkells() throws Exception 
{
        Document top = DocumentFactory.getInstance().createDocument();
        Element root = top.addElement("root");
        root.addElement("child1").addElement("child11");
        root.addElement("child2").addElement("child21");
        System.out.println(top.asXML());
        XPath test1 = top.createXPath("/root/child1/child11");
        XPath test2 = top.createXPath("/root/child2/child21");
        Node position1 = test1.selectSingleNode(root);
        Node position2 = test2.selectSingleNode(root);
        System.out.println("test1= " + test1);
        System.out.println("test2= " + test2);
        System.out.println("Position1 Xpath = " + position1.getUniquePath());
        System.out.println("Position2 Xpath = " + position2.getUniquePath());
        System.out.println("test2.matches(position1) : "
                + test2.matches(position1));
        assertTrue("test1.matches(position1)", test1.matches(position1));
        assertTrue("test2.matches(position2)", test2.matches(position2));
        assertTrue("test2.matches(position1) should be false", !test2
                .matches(position1));
}

Test found by Mike Skells

 public  void testRobLebowitz() throws Exception 
{
        String text = "< ul >" + "    < ul >" + "        < li/ >"
                + "            < ul >" + "                < li/ >"
                + "            < /ul >" + "        < li/ >" + "    < /ul >" + "< /ul >";
        Document document = DocumentHelper.parseText(text);
        List lists = document.selectNodes("//ul | //ol");
        int count = 0;
        for (int i = 0; i <  lists.size(); i++) {
            Element list = (Element) lists.get(i);
            List nodes = list.selectNodes("ancestor::ul");
            if ((nodes != null) && (nodes.size()  > 0)) {
                continue;
            }
            nodes = list.selectNodes("ancestor::ol");
            if ((nodes != null) && (nodes.size()  > 0)) {
                continue;
            }
        }
}

A bug found by Rob Lebowitz

 public  void testStefan() throws Exception 
{
        String text = "< foo >hello< /foo >";
        Document document = DocumentHelper.parseText(text);
        XPath xpath = DocumentHelper.createXPath("/x");
        Object value = xpath.evaluate(document);
}

A bug found by Stefan which results in IndexOutOfBoundsException for empty results

 public  void testXPaths() throws Exception 
{
        Document document = getDocument("/xml/rabo1ae.xml");
        Element root = (Element) document
                .selectSingleNode("/m:Msg/m:Contents/m:Content");
        assertTrue("root is not null", root != null);
        Namespace ns = root.getNamespaceForPrefix("ab");
        assertTrue("Found namespace", ns != null);
        System.out.println("Found: " + ns.getURI());
        Element element = (Element) root
                .selectSingleNode("ab:RaboPayLoad[@id='1234123']");
        assertTrue("element is not null", element != null);
        String value = element.valueOf("ab:AccountingEntry/ab:RateType");
        assertEquals("RateType is correct", "CRRNT", value);
}