Program: 65003
Project: 65003
Buggy source:
private XPathFragment openGroupingElementsForQName(QName fieldValue,MarshalRecord marshalRecord){
  XPathFragment xPathFragment=null;
  ArrayList<XPathNode> groupingElements=marshalRecord.getGroupingElements();
  NamespaceResolver namespaceResolver=marshalRecord.getNamespaceResolver();
  if ((fieldValue.getNamespaceURI() == null || fieldValue.getNamespaceURI().equals("String_Node_Str")) && marshalRecord.getNamespaceResolver().getDefaultNamespaceURI() != null) {
    for (int x=0, groupingElementsSize=groupingElements.size(); x < groupingElementsSize; x++) {
      XPathNode xPathNode=groupingElements.get(x);
      xPathFragment=xPathNode.getXPathFragment();
      if (x == (groupingElements.size() - 1) && namespaceResolver.getDefaultNamespaceURI().equals(xPathFragment.getNamespaceURI()) && xPathFragment.getPrefix() == null) {
        String prefix=namespaceResolver.generatePrefix();
        String xPath=prefix + "String_Node_Str" + xPathFragment.getShortName();
        XPathFragment newFragment=new XPathFragment(xPath);
        newFragment.setNamespaceURI(namespaceResolver.getDefaultNamespaceURI());
        marshalRecord.openStartElement(newFragment,namespaceResolver);
        marshalRecord.namespaceDeclaration(prefix,namespaceResolver.getDefaultNamespaceURI());
        marshalRecord.predicateAttribute(xPathFragment,namespaceResolver);
        xPathFragment=newFragment;
      }
 else {
        marshalRecord.openStartElement(xPathFragment,namespaceResolver);
        marshalRecord.predicateAttribute(xPathFragment,namespaceResolver);
        marshalRecord.closeStartElement();
      }
    }
    marshalRecord.setGroupingElement(null);
  }
  return xPathFragment;
}

Fixed version (ground truth):
private XPathFragment openGroupingElementsForQName(QName fieldValue,MarshalRecord marshalRecord){
  XPathFragment xPathFragment=null;
  ArrayList<XPathNode> groupingElements=marshalRecord.getGroupingElements();
  NamespaceResolver namespaceResolver=marshalRecord.getNamespaceResolver();
  if ((fieldValue.getNamespaceURI() == null || fieldValue.getNamespaceURI().equals(XMLConstants.EMPTY_STRING)) && marshalRecord.getNamespaceResolver().getDefaultNamespaceURI() != null) {
    for (int x=0, groupingElementsSize=groupingElements.size(); x < groupingElementsSize; x++) {
      XPathNode xPathNode=groupingElements.get(x);
      xPathFragment=xPathNode.getXPathFragment();
      if (x == (groupingElements.size() - 1) && namespaceResolver.getDefaultNamespaceURI().equals(xPathFragment.getNamespaceURI()) && xPathFragment.getPrefix() == null) {
        String prefix=namespaceResolver.generatePrefix();
        String xPath=prefix + XMLConstants.COLON + xPathFragment.getShortName();
        XPathFragment newFragment=new XPathFragment(xPath);
        newFragment.setNamespaceURI(namespaceResolver.getDefaultNamespaceURI());
        marshalRecord.openStartElement(newFragment,namespaceResolver);
        marshalRecord.namespaceDeclaration(prefix,namespaceResolver.getDefaultNamespaceURI());
        marshalRecord.predicateAttribute(xPathFragment,namespaceResolver);
        xPathFragment=newFragment;
      }
 else {
        marshalRecord.openStartElement(xPathFragment,namespaceResolver);
        marshalRecord.predicateAttribute(xPathFragment,namespaceResolver);
        marshalRecord.closeStartElement();
      }
    }
    marshalRecord.setGroupingElement(null);
  }
  return xPathFragment;
}