Program: 89773
Project: 89773
Buggy source:
/** 
 * Get a connection to our database. If a connection is already registered  to the current thread, checks that it is valid, and if not renews it.  Assumes that AutoCommit is true.
 * @param dbUrl The url to the database.
 * @return a connection to our database.
 * @throws IOFailure if we cannot connect to the database (or find thedriver).
 * @throws ArgumentNotValid If the dbUrl is either null or the empty string.
 */
public static Connection getDBConnection(String dbUrl) throws IOFailure, ArgumentNotValid {
  ArgumentNotValid.checkNotNullOrEmpty(dbUrl,"String_Node_Str");
  try {
    int validityCheckTimeout=Settings.getInt(CommonSettings.DB_CONN_VALID_CHECK_TIMEOUT);
    Connection connection=connectionPool.get(Thread.currentThread());
    boolean renew=((connection == null) || (!connection.isValid(validityCheckTimeout)));
    if (renew) {
      Class.forName(DBSpecifics.getInstance().getDriverClassName());
      connection=DriverManager.getConnection(dbUrl);
      connectionPool.put(Thread.currentThread(),connection);
      log.info("String_Node_Str" + dbUrl + "String_Node_Str"+ DBSpecifics.getInstance().getDriverClassName()+ "String_Node_Str");
    }
    return connection;
  }
 catch (  ClassNotFoundException e) {
    final String message="String_Node_Str" + DBSpecifics.getInstance().getDriverClassName() + "String_Node_Str";
    log.warn(message,e);
    throw new IOFailure(message,e);
  }
catch (  SQLException e) {
    final String message="String_Node_Str" + dbUrl + "String_Node_Str"+ DBSpecifics.getInstance().getDriverClassName()+ "String_Node_Str"+ "String_Node_Str"+ ExceptionUtils.getSQLExceptionCause(e);
    log.warn(message,e);
    throw new IOFailure(message,e);
  }
}

Fixed version (ground truth):
/** 
 * Get a connection to our database. If a connection is already registered  to the current thread, checks that it is valid, and if not renews it.  This sets AutoCommit to false as part of getting a fresh connection.
 * @param dbUrl The url to the database.
 * @return a connection to our database.
 * @throws IOFailure if we cannot connect to the database (or find thedriver).
 * @throws ArgumentNotValid If the dbUrl is either null or the empty string.
 */
public static Connection getDBConnection(String dbUrl) throws IOFailure, ArgumentNotValid {
  ArgumentNotValid.checkNotNullOrEmpty(dbUrl,"String_Node_Str");
  try {
    int validityCheckTimeout=Settings.getInt(CommonSettings.DB_CONN_VALID_CHECK_TIMEOUT);
    Connection connection=connectionPool.get(Thread.currentThread());
    boolean renew=((connection == null) || (!connection.isValid(validityCheckTimeout)));
    if (renew) {
      Class.forName(DBSpecifics.getInstance().getDriverClassName());
      connection=DriverManager.getConnection(dbUrl);
      connection.setAutoCommit(false);
      connectionPool.put(Thread.currentThread(),connection);
      log.info("String_Node_Str" + dbUrl + "String_Node_Str"+ DBSpecifics.getInstance().getDriverClassName()+ "String_Node_Str");
    }
    return connection;
  }
 catch (  ClassNotFoundException e) {
    final String message="String_Node_Str" + DBSpecifics.getInstance().getDriverClassName() + "String_Node_Str";
    log.warn(message,e);
    throw new IOFailure(message,e);
  }
catch (  SQLException e) {
    final String message="String_Node_Str" + dbUrl + "String_Node_Str"+ DBSpecifics.getInstance().getDriverClassName()+ "String_Node_Str"+ "String_Node_Str"+ ExceptionUtils.getSQLExceptionCause(e);
    log.warn(message,e);
    throw new IOFailure(message,e);
  }
}