Program: 68220
Project: 68220
Buggy source:
private void namespaceQualifyFragment(Element next,List<String> declaredPrefixes){
  String elementUri=next.getNamespaceURI();
  String elementPrefix=next.getPrefix();
  if (elementPrefix != null) {
    Attr namespaceDeclaration=next.getAttributeNode(XMLConstants.XMLNS + "String_Node_Str" + elementPrefix);
    if ((null == namespaceDeclaration) && !declaredPrefixes.contains(elementPrefix)) {
      (next).setAttributeNS(XMLConstants.XMLNS_URL,XMLConstants.XMLNS + "String_Node_Str" + elementPrefix,elementUri);
      declaredPrefixes.add(elementPrefix);
    }
  }
  NamedNodeMap attributes=next.getAttributes();
  int attributesSize=attributes.getLength();
  for (int i=0; i < attributesSize; i++) {
    Attr nextAttribute=(Attr)attributes.item(i);
    String attributePrefix=nextAttribute.getPrefix();
    if (attributePrefix != null) {
      if (XMLConstants.XMLNS_URL.equals(nextAttribute.getNamespaceURI())) {
        declaredPrefixes.add(nextAttribute.getLocalName());
      }
 else {
        Attr namespaceDeclaration=next.getAttributeNode(XMLConstants.XMLNS + "String_Node_Str" + attributePrefix);
        if ((null == namespaceDeclaration) && !declaredPrefixes.contains(attributePrefix)) {
          String attributeUri=nextAttribute.getNamespaceURI();
          (next).setAttributeNS(XMLConstants.XMLNS_URL,XMLConstants.XMLNS + "String_Node_Str" + attributePrefix,attributeUri);
          declaredPrefixes.add(attributePrefix);
        }
        if (XMLConstants.SCHEMA_INSTANCE_URL.equals(nextAttribute.getNamespaceURI()) && XMLConstants.SCHEMA_TYPE_ATTRIBUTE.equals(nextAttribute.getLocalName())) {
          String value=nextAttribute.getValue();
          int colonIndex=value.indexOf(':');
          if (colonIndex > -1) {
            String prefix=value.substring(0,colonIndex);
            namespaceDeclaration=next.getAttributeNode(XMLConstants.XMLNS + "String_Node_Str" + prefix);
            if ((null == namespaceDeclaration) && !declaredPrefixes.contains(prefix)) {
              String uri=XMLPlatformFactory.getInstance().getXMLPlatform().resolveNamespacePrefix(next,prefix);
              (next).setAttributeNS(XMLConstants.XMLNS_URL,XMLConstants.XMLNS + "String_Node_Str" + prefix,uri);
              declaredPrefixes.add(prefix);
            }
          }
        }
      }
    }
  }
  NodeList children=next.getChildNodes();
  for (int i=0; i < children.getLength(); i++) {
    Node nextNode=children.item(i);
    if (nextNode.getNodeType() == Node.ELEMENT_NODE) {
      Element child=(Element)nextNode;
      namespaceQualifyFragment(child,declaredPrefixes);
    }
  }
}

Fixed version (ground truth):
private void namespaceQualifyFragment(Element next,List<String> declaredPrefixes){
  String elementUri=next.getNamespaceURI();
  String elementPrefix=next.getPrefix();
  if (elementPrefix != null) {
    Attr namespaceDeclaration=next.getAttributeNode(XMLConstants.XMLNS + "String_Node_Str" + elementPrefix);
    if ((null == namespaceDeclaration) && !declaredPrefixes.contains(elementPrefix)) {
      (next).setAttributeNS(XMLConstants.XMLNS_URL,XMLConstants.XMLNS + "String_Node_Str" + elementPrefix,elementUri);
      declaredPrefixes.add(elementPrefix);
    }
  }
  NamedNodeMap attributes=next.getAttributes();
  int attributesSize=attributes.getLength();
  for (int i=0; i < attributesSize; i++) {
    Attr nextAttribute=(Attr)attributes.item(i);
    String attributePrefix=nextAttribute.getPrefix();
    if (attributePrefix != null) {
      if (XMLConstants.XMLNS_URL.equals(nextAttribute.getNamespaceURI())) {
        declaredPrefixes.add(nextAttribute.getLocalName());
      }
 else {
        Attr namespaceDeclaration=next.getAttributeNode(XMLConstants.XMLNS + "String_Node_Str" + attributePrefix);
        if ((null == namespaceDeclaration) && !declaredPrefixes.contains(attributePrefix)) {
          String attributeUri=nextAttribute.getNamespaceURI();
          (next).setAttributeNS(XMLConstants.XMLNS_URL,XMLConstants.XMLNS + "String_Node_Str" + attributePrefix,attributeUri);
          declaredPrefixes.add(attributePrefix);
        }
        if (XMLConstants.SCHEMA_INSTANCE_URL.equals(nextAttribute.getNamespaceURI()) && XMLConstants.SCHEMA_TYPE_ATTRIBUTE.equals(nextAttribute.getLocalName())) {
          String value=nextAttribute.getValue();
          int colonIndex=value.indexOf(':');
          if (colonIndex > -1) {
            String prefix=value.substring(0,colonIndex);
            namespaceDeclaration=next.getAttributeNode(XMLConstants.XMLNS + "String_Node_Str" + prefix);
            if ((null == namespaceDeclaration) && !declaredPrefixes.contains(prefix)) {
              String uri=XMLPlatformFactory.getInstance().getXMLPlatform().resolveNamespacePrefix(next,prefix);
              (next).setAttributeNS(XMLConstants.XMLNS_URL,XMLConstants.XMLNS + "String_Node_Str" + prefix,uri);
              declaredPrefixes.add(prefix);
            }
          }
        }
      }
    }
  }
  NodeList children=next.getChildNodes();
  int numberOfNodes=children.getLength();
  for (int i=0; i < numberOfNodes; i++) {
    Node nextNode=children.item(i);
    if (nextNode.getNodeType() == Node.ELEMENT_NODE) {
      Element child=(Element)nextNode;
      namespaceQualifyFragment(child,declaredPrefixes);
    }
  }
}