Program: 53218
Project: 53218
Buggy source:
public String assertPackageImportXML(final String xml,final Path resource){
  if (packageHeaderInfo.getHeader() == null) {
    return xml;
  }
  final Imports imports=ImportsParser.parseImports(packageHeaderInfo.getHeader());
  if (imports == null) {
    return xml;
  }
  DocumentBuilderFactory domfac=DocumentBuilderFactory.newInstance();
  try {
    DocumentBuilder dombuilder=domfac.newDocumentBuilder();
    Document doc=dombuilder.parse(new ByteArrayInputStream(xml.getBytes()));
    if (doc.getElementsByTagName("String_Node_Str").getLength() != 0) {
      return xml;
    }
    Element root=doc.getDocumentElement();
    Element topImportsElement=doc.createElement("String_Node_Str");
    Element nestedImportsElement=doc.createElement("String_Node_Str");
    topImportsElement.appendChild(nestedImportsElement);
    for (    final Import i : imports.getImports()) {
      Element importElement=doc.createElement(Import.class.getCanonicalName());
      Element typeElement=doc.createElement("String_Node_Str");
      typeElement.appendChild(doc.createTextNode(i.getType()));
      importElement.appendChild(typeElement);
      nestedImportsElement.appendChild(importElement);
    }
    root.appendChild(topImportsElement);
    TransformerFactory transfac=TransformerFactory.newInstance();
    Transformer trans=transfac.newTransformer();
    trans.setOutputProperty(OutputKeys.METHOD,"String_Node_Str");
    trans.setOutputProperty(OutputKeys.INDENT,"String_Node_Str");
    trans.setOutputProperty("String_Node_Str",Integer.toString(2));
    StringWriter sw=new StringWriter();
    StreamResult result=new StreamResult(sw);
    DOMSource s=new DOMSource(root);
    trans.transform(s,result);
    String xmlString=sw.toString();
    if (xmlString != null)     xmlString=xmlString.substring(xmlString.indexOf("String_Node_Str") + 1);
    return xmlString;
  }
 catch (  TransformerConfigurationException e) {
    e.printStackTrace();
  }
catch (  ParserConfigurationException e) {
    e.printStackTrace();
  }
catch (  FileNotFoundException e) {
    e.printStackTrace();
  }
catch (  SAXException e) {
    e.printStackTrace();
  }
catch (  IOException e) {
    e.printStackTrace();
  }
catch (  TransformerException e) {
    e.printStackTrace();
  }
  return xml;
}

Fixed version (ground truth):
public String assertPackageImportXML(final String xml,final Path resource){
  if (packageHeaderInfo.getHeader() == null) {
    return xml;
  }
  final Imports imports=ImportsParser.parseImports(packageHeaderInfo.getHeader());
  if (imports == null) {
    return xml;
  }
  DocumentBuilderFactory domfac=DocumentBuilderFactory.newInstance();
  try {
    DocumentBuilder dombuilder=domfac.newDocumentBuilder();
    Document doc=dombuilder.parse(new ByteArrayInputStream(xml.getBytes(Charsets.UTF_8)));
    if (doc.getElementsByTagName("String_Node_Str").getLength() != 0) {
      return xml;
    }
    Element root=doc.getDocumentElement();
    Element topImportsElement=doc.createElement("String_Node_Str");
    Element nestedImportsElement=doc.createElement("String_Node_Str");
    topImportsElement.appendChild(nestedImportsElement);
    for (    final Import i : imports.getImports()) {
      Element importElement=doc.createElement(Import.class.getCanonicalName());
      Element typeElement=doc.createElement("String_Node_Str");
      typeElement.appendChild(doc.createTextNode(i.getType()));
      importElement.appendChild(typeElement);
      nestedImportsElement.appendChild(importElement);
    }
    root.appendChild(topImportsElement);
    TransformerFactory transfac=TransformerFactory.newInstance();
    Transformer trans=transfac.newTransformer();
    trans.setOutputProperty(OutputKeys.METHOD,"String_Node_Str");
    trans.setOutputProperty(OutputKeys.INDENT,"String_Node_Str");
    trans.setOutputProperty("String_Node_Str",Integer.toString(2));
    StringWriter sw=new StringWriter();
    StreamResult result=new StreamResult(sw);
    DOMSource s=new DOMSource(root);
    trans.transform(s,result);
    String xmlString=sw.toString();
    if (xmlString != null)     xmlString=xmlString.substring(xmlString.indexOf("String_Node_Str") + 1);
    return xmlString;
  }
 catch (  TransformerConfigurationException e) {
    e.printStackTrace();
  }
catch (  ParserConfigurationException e) {
    e.printStackTrace();
  }
catch (  FileNotFoundException e) {
    e.printStackTrace();
  }
catch (  SAXException e) {
    e.printStackTrace();
  }
catch (  IOException e) {
    e.printStackTrace();
  }
catch (  TransformerException e) {
    e.printStackTrace();
  }
  return xml;
}