Program: 66343
Project: 66343
Buggy source:
private void openAndCloseStartElement(){
  try {
    if (namespaceURI == null) {
      Iterator attributesIterator=null;
      if (null != attributes) {
        attributesIterator=attributes.iterator();
      }
      Iterator namespaceDeclarationsIterator=null;
      if (null != namespaceDeclarations) {
        namespaceDeclarationsIterator=namespaceDeclarations.iterator();
      }
      xmlEventWriter.add(xmlEventFactory.createStartElement(XMLConstants.EMPTY_STRING,XMLConstants.EMPTY_STRING,xPathFragment.getLocalName(),attributesIterator,namespaceDeclarationsIterator));
      String defaultNamespace=xmlEventWriter.getNamespaceContext().getNamespaceURI(XMLConstants.EMPTY_STRING);
      if (defaultNamespace != null && defaultNamespace.length() > 0) {
        this.xmlEventWriter.setDefaultNamespace(XMLConstants.EMPTY_STRING);
        this.xmlEventWriter.add(xmlEventFactory.createNamespace(XMLConstants.EMPTY_STRING));
      }
    }
 else {
      String prefix=xPathFragment.getPrefix();
      if (prefix == null) {
        prefix=XMLConstants.EMPTY_STRING;
      }
      Iterator attributesIterator=null;
      if (null != attributes) {
        attributesIterator=attributes.iterator();
      }
      Iterator namespaceDeclarationsIterator=null;
      if (null != namespaceDeclarations) {
        namespaceDeclarationsIterator=namespaceDeclarations.iterator();
      }
      XMLEvent startElement=this.xmlEventFactory.createStartElement(prefix,namespaceURI,xPathFragment.getLocalName(),attributesIterator,namespaceDeclarationsIterator);
      xmlEventWriter.add(startElement);
    }
  }
 catch (  XMLStreamException ex) {
    throw XMLMarshalException.marshalException(ex);
  }
}

Fixed version (ground truth):
private void openAndCloseStartElement(){
  try {
    String namespaceURI=xPathFragment.getNamespaceURI();
    if (null == namespaceURI) {
      Iterator attributesIterator=null;
      if (null != attributes) {
        attributesIterator=attributes.iterator();
      }
      Iterator namespaceDeclarationsIterator=null;
      if (null != namespaceDeclarations) {
        namespaceDeclarationsIterator=namespaceDeclarations.iterator();
      }
      xmlEventWriter.add(xmlEventFactory.createStartElement(XMLConstants.EMPTY_STRING,XMLConstants.EMPTY_STRING,xPathFragment.getLocalName(),attributesIterator,namespaceDeclarationsIterator));
      String defaultNamespace=xmlEventWriter.getNamespaceContext().getNamespaceURI(XMLConstants.EMPTY_STRING);
      if (defaultNamespace != null && defaultNamespace.length() > 0) {
        xmlEventWriter.setDefaultNamespace(XMLConstants.EMPTY_STRING);
        xmlEventWriter.add(xmlEventFactory.createNamespace(XMLConstants.EMPTY_STRING));
      }
    }
 else {
      String prefix=xPathFragment.getPrefix();
      if (null == prefix) {
        prefix=XMLConstants.EMPTY_STRING;
      }
      Iterator attributesIterator=null;
      if (null != attributes) {
        attributesIterator=attributes.iterator();
      }
      Iterator namespaceDeclarationsIterator=null;
      if (null != namespaceDeclarations) {
        namespaceDeclarationsIterator=namespaceDeclarations.iterator();
      }
      xmlEventWriter.add(xmlEventFactory.createStartElement(prefix,namespaceURI,xPathFragment.getLocalName(),attributesIterator,namespaceDeclarationsIterator));
    }
  }
 catch (  XMLStreamException ex) {
    throw XMLMarshalException.marshalException(ex);
  }
}