Program: 133651
Project: 133651
Buggy source:
/** 
 * Disconnects the associated   {@link #connection} if not alreadydisconnected. <p> <b>Note:</b> This method is <i>not</i> intended to be overridden by sub-classes. </p>
 * @param block If true, then the calling thread will be blocked until the disconnection succeeds or fails. If false, then the disconnection process will not block the calling thread.
 * @return True if the connection is closed upon returning, false otherwise.
 */
public boolean disconnect(boolean block){
  boolean connected=false;
  String key=getKey();
  System.out.println("String_Node_Str" + "String_Node_Str" + key + "String_Node_Str"+ (block ? "String_Node_Str" : "String_Node_Str")+ "String_Node_Str");
  if (state == ConnectionState.Connected) {
    connected=true;
    System.out.println("String_Node_Str" + "String_Node_Str" + key + "String_Node_Str");
    Thread thread=new Thread(){
      @Override public void run(){
        if (closeConnection(connection)) {
          setState(ConnectionState.Disconnected);
          connection=null;
        }
      }
    }
;
    thread.setDaemon(false);
    thread.start();
    if (block) {
      try {
        thread.join();
        connected=(state == ConnectionState.Disconnected);
      }
 catch (      InterruptedException e) {
        System.err.println("String_Node_Str" + "String_Node_Str" + key + "String_Node_Str");
        e.printStackTrace();
      }
    }
  }
 else {
    System.out.println("String_Node_Str" + "String_Node_Str" + key + "String_Node_Str");
  }
  return !connected;
}

Fixed version (ground truth):
/** 
 * Disconnects the associated   {@link #connection} if not alreadydisconnected. <p> <b>Note:</b> This method is <i>not</i> intended to be overridden by sub-classes. </p>
 * @param block If true, then the calling thread will be blocked until the disconnection succeeds or fails. If false, then the disconnection process will not block the calling thread.
 * @return True if the connection is closed upon returning, false otherwise.
 */
public boolean disconnect(boolean block){
  String key=getKey();
  System.out.println("String_Node_Str" + "String_Node_Str" + key + "String_Node_Str"+ (block ? "String_Node_Str" : "String_Node_Str")+ "String_Node_Str");
  if (state == ConnectionState.Connected) {
    System.out.println("String_Node_Str" + "String_Node_Str" + key + "String_Node_Str");
    Thread thread=new Thread(){
      @Override public void run(){
        if (closeConnection(connection)) {
          setState(ConnectionState.Disconnected);
          connection=null;
        }
      }
    }
;
    thread.setDaemon(false);
    thread.start();
    if (block) {
      try {
        thread.join();
      }
 catch (      InterruptedException e) {
        System.err.println("String_Node_Str" + "String_Node_Str" + key + "String_Node_Str");
        e.printStackTrace();
      }
    }
  }
 else   if (state == ConnectionState.Connecting) {
    System.out.println("String_Node_Str" + "String_Node_Str" + key + "String_Node_Str");
  }
 else {
    System.out.println("String_Node_Str" + "String_Node_Str" + key + "String_Node_Str");
    setState(ConnectionState.Disconnected);
  }
  return state == ConnectionState.Disconnected;
}