[XMLBEANS-583] Duplicated "xmlns" attribute in XmlObject.toString() result

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: Version 5.0.0
• Fix Version/s: Version 5.0.3

Language

Java

• Assignee: PJ Fanning
• Reporter: Dmitry Lastochkin
• Created: 22/Dec/21 17:42
• Updated: 24/Dec/21 08:58
• Resolved: 23/Dec/21 22:13

Description

Hello!
I ran into the following problem: in some cases, XmlObject.toString() returns an XML containing duplicated "xmlns" attribute, as shown bellow

<Ns2E1 xmlns="XmlToStringTest2Xsd.xsd">

  <Ns2T1E1 xmlns="" xmlns="XmlToStringTest2Xsd.xsd">

    <Ns1T1E1 xmlns="XmlToStringTest1Xsd.xsd">Ns1T1E1</Ns1T1E1>

  </Ns2T1E1>

</Ns2E1>

I wrote a simple test that reproduces the error (you can find test XSDs in schemas.zip):

public class XmlToStringTest {
    @Test
    public void test() {
        try {
            final Ns2E1Document ns2e1Doc = Ns2E1Document.Factory.newInstance();
            ns2e1Doc.addNewNs2E1().addNewNs2T1E1().setNs1T1E1("Ns1T1E1");
            
            final Ns3E1Document ns3e1Doc = Ns3E1Document.Factory.newInstance();
            ns3e1Doc.addNewNs3E1().setNs3T1E1(Ns1T1.Factory.parse(ns2e1Doc.getNs2E1().getNs2T1E1().toString()));
            
            final Ns3E1Document pNs3e1Doc = Ns3E1Document.Factory.parse(ns3e1Doc.toString());
            final Ns2E1Document pNs2e1Doc = Ns2E1Document.Factory.newInstance();
            pNs2e1Doc.addNewNs2E1().setNs2T1E1(pNs3e1Doc.getNs3E1().getNs3T1E1());
            
            System.out.println(pNs2e1Doc.toString());
            Ns2E1Document.Factory.parse(pNs2e1Doc.toString());
        } catch (Exception ex) {
            ex.printStackTrace();
            Assert.fail();
        }
    }
}

I investigated the problem and found the cause. In the Saver.tryPrefix() I found the following comment:

// If the prefix is currently mapped, then try another prefix. A
// special case is that of trying to map the default prefix ("").
// Here, there always exists a default mapping. If this is the
// mapping we found, then remap it anyways. I use != to compare
// strings because I want to test for the specific initial default
// uri I added when I initialized the saver.

But the code following this comment looks like this:

return existingUri == null || (prefix.length() <= 0 && Objects.equals(existingUri, _initialDefaultUri)); // Objects.equals, not ==

And _initialDefaultUri initialized like this:

_initialDefaultUri = "";

But should be

_initialDefaultUri = new String("");

because we talk about a specific value.

Hopefully this information helps fix this bug.