Missing namespace when marshalling org.w3c.dom.Element with namespaced attribute

[blutorange]

Describe the bug

When MOXY marshals an org.w3c.dom.Element, it correctly includes the namespace of the element. However, any namespaces for attributes are ignored and never make it into the marshalled XML, leading to invalid XML files.

For example, let's say you have the following annotated class:

@XmlRootElement(name = "bugdemo.MyXmlAnyElementType")
public class MyXmlAnyElementType {
	@XmlAnyElement(lax = false)
	public Element someXmlBlock;
}

And you create an instance with some DOM element with a namespace attribute:

MyXmlAnyElementType el = new MyXmlAnyElementType();

Document doc = newDocument();
Element x = doc.createElementNS("http://example.com/element", "x");
x.setAttributeNS("http://example.com/attribute", "attr", "value");
Element y = doc.createElementNS("http://example.com/element2", "y");
x.appendChild(y);

el.someXmlBlock = x;

Then moxy creates the following XML

<?xml version="1.0" encoding="UTF-8"?>
<bugdemo.MyXmlAnyElementType xmlns="urn:testcase">
   <x attr="value" xmlns="http://example.com/element">
      <y xmlns="http://example.com/element2"/>
   </x>
</bugdemo.MyXmlAnyElementType>

The default glassfish JAXB implementation produces correct XML:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<bugdemo.MyXmlAnyElementType xmlns="urn:testcase">
    <x ns0:attr="value" xmlns="http://example.com/element" xmlns:ns0="http://example.com/attribute">
        <y xmlns="http://example.com/element2"/>
    </x>
</bugdemo.MyXmlAnyElementType>

Context: I first encountered it with generated Java files for the BPMN2 XSD schema files (which allows custom extension elements).

To Reproduce

Reproducer: https://github.com/blutorange/moxybug/tree/demo-bug-attr-ns

Simply run mvn test. Seems to happen with any namespaced attribute.

https://github.com/blutorange/moxybug/blob/4fcfc78178f15d22d88177d008a1660ada70ea1a/src/test/java/bugdemo/Testcase.java#L26-L43

• EclipseLink version: 4.0.5
• Java/JDK version: 17

Expected behavior

Moxy should output XML where the namespace of the attribute matches the namespace as defined programmatically in the org.w3c.dom.Element.

Note

Manually setting a prefix on the org.w3c.dom.Attr results in moxy outputting the prefix, but it's still missing the namespace.

From a little big of debugging, I found XMLFragmentReader#handlePrefixedAttribute, and while that method inspects an element's attributes, it only seems to check for xmlns and ignores everything else. That method seems to be responsible for why it works for org.w3c.dom.Element

eclipselink/foundation/org.eclipse.persistence.core/src/main/java/org/eclipse/persistence/internal/oxm/record/XMLFragmentReader.java

Lines 131 to 150 in 234c8fa

	if(attributes != null) {
	for(int x=0; x < attributes.getLength(); x++) {
	Node attribute = attributes.item(x);
	if(XMLConstants.XMLNS_ATTRIBUTE.equals(attribute.getPrefix())) {
	NamespaceResolver tmpresolver = getTempResolver(elem);
	tmpresolver.put(attribute.getLocalName(), attribute.getNodeValue());
	if (!nsresolverList.contains(tmpresolver)) {
	nsresolverList.add(tmpresolver);
	}
	} else if(XMLConstants.XMLNS_ATTRIBUTE.equals(attribute.getNodeName())) {
	NamespaceResolver tmpresolver = getTempResolver(elem);
	String namespace = attribute.getNodeValue();
	if(null == namespace) {
	namespace = Constants.EMPTY_STRING;
	}
	tmpresolver.put(Constants.EMPTY_STRING, namespace);
	if (!nsresolverList.contains(tmpresolver)) {
	nsresolverList.add(tmpresolver);
	}
	}