Program: 86700
Project: 86700
Buggy source:
/** 
 * Updates an already existing element in the document. IMPORTANT: the lengths of fields and content array must have been checked before this method is called!
 * @param file
 * @param table
 * @param fields
 * @param values
 * @throws IOException
 * @throws DatabaseTableInconsistencyException
 * @throws DatabaseWriteException
 */
private void updateData(File file,Document table,DataAccess data,String[] fields,Object[] values) throws IOException, DatabaseTableInconsistencyException, DatabaseWriteException {
  boolean hasUpdated=false;
  for (  Element element : table.getRootElement().getChildren()) {
    int equalFields=0;
    for (int i=0; i < fields.length; ++i) {
      Element child=element.getChild(fields[i]);
      if (child != null) {
        if (child.getText().equals(String.valueOf(values[i]))) {
          equalFields++;
        }
      }
    }
    if (equalFields != fields.length) {
      continue;
    }
    if (data.isInconsistent()) {
      throw new DatabaseTableInconsistencyException("String_Node_Str");
    }
    HashMap<Column,Object> dataSet=data.toDatabaseEntryList();
    for (    Column column : dataSet.keySet()) {
      Element child=element.getChild(column.columnName());
      if (child == null) {
        throw new DatabaseTableInconsistencyException("String_Node_Str" + column.columnName() + "String_Node_Str");
      }
      if (column.autoIncrement()) {
        continue;
      }
      addToElement(table,child,dataSet.get(column),column);
      hasUpdated=true;
    }
  }
  if (hasUpdated) {
    file.setWritable(true);
    RandomAccessFile f=new RandomAccessFile(file,"String_Node_Str");
    f.getChannel().lock();
    OutputStream out=new FileOutputStream(file,false);
    xmlSerializer.output(table,out);
    f.close();
    out.close();
  }
 else {
    insert(data);
  }
}

Fixed version (ground truth):
/** 
 * Updates an already existing element in the document. IMPORTANT: the lengths of fields and content array must have been checked before this method is called!
 * @param file
 * @param table
 * @param fields
 * @param values
 * @throws IOException
 * @throws DatabaseTableInconsistencyException
 * @throws DatabaseWriteException
 */
private void updateData(File file,Document table,DataAccess data,String[] fields,Object[] values) throws IOException, DatabaseTableInconsistencyException, DatabaseWriteException {
  boolean hasUpdated=false;
  for (  Element element : table.getRootElement().getChildren()) {
    int equalFields=0;
    for (int i=0; i < fields.length; ++i) {
      Element child=element.getChild(fields[i]);
      if (child != null) {
        if (child.getText().equals(String.valueOf(values[i]))) {
          equalFields++;
        }
      }
    }
    if (equalFields != fields.length) {
      continue;
    }
    if (data.isInconsistent()) {
      throw new DatabaseTableInconsistencyException("String_Node_Str");
    }
    HashMap<Column,Object> dataSet=data.toDatabaseEntryList();
    for (    Column column : dataSet.keySet()) {
      Element child=element.getChild(column.columnName());
      if (child == null) {
        throw new DatabaseTableInconsistencyException("String_Node_Str" + column.columnName() + "String_Node_Str");
      }
      if (column.autoIncrement()) {
        continue;
      }
      addToElement(table,child,dataSet.get(column),column);
      hasUpdated=true;
    }
  }
  if (hasUpdated) {
    file.setWritable(true);
    RandomAccessFile f=new RandomAccessFile(file,"String_Node_Str");
    f.getChannel().lock();
    f.setLength(0);
    FileWriter writer=new FileWriter(f.getFD());
    xmlSerializer.output(table,writer);
    f.close();
  }
 else {
    insert(data);
  }
}