Program: 99432
Project: 99432
Buggy source:
/** 
 * Constructor
 * @param context the Context
 * @param usbManager the UsbManager
 * @param deviceAttachedListener the OnMidiDeviceAttachedListener
 */
public MidiDeviceConnectionWatcher(@NonNull Context context,@NonNull UsbManager usbManager,@NonNull OnMidiDeviceAttachedListener deviceAttachedListener,@NonNull final OnMidiDeviceDetachedListener deviceDetachedListener){
  this.context=context;
  this.usbManager=usbManager;
  deviceGrantQueue=new LinkedList<UsbDevice>();
  isGranting=false;
  grantingDevice=null;
  grantedDevices=new HashSet<UsbDevice>();
  deviceDetachedHandler=new Handler(new Handler.Callback(){
    @Override public boolean handleMessage(    Message message){
      UsbDevice detachedDevice=(UsbDevice)message.obj;
      deviceDetachedListener.onDeviceDetached(detachedDevice);
      AsyncTask<UsbDevice,Void,Void> task=new AsyncTask<UsbDevice,Void,Void>(){
        @Override protected Void doInBackground(        UsbDevice... params){
          if (params == null || params.length < 1) {
            return null;
          }
          UsbDevice usbDevice=params[0];
          Set<MidiInputDevice> inputDevices=midiInputDevices.get(usbDevice);
          if (inputDevices != null && inputDevices.size() > 0) {
            for (            MidiInputDevice inputDevice : inputDevices) {
              if (inputDevice != null) {
                inputDevice.stop();
                deviceDetachedListener.onMidiInputDeviceDetached(inputDevice);
              }
            }
            midiInputDevices.remove(usbDevice);
          }
          Set<MidiOutputDevice> outputDevices=midiOutputDevices.get(usbDevice);
          if (outputDevices != null) {
            for (            MidiOutputDevice outputDevice : outputDevices) {
              if (outputDevice != null) {
                outputDevice.stop();
                deviceDetachedListener.onMidiOutputDeviceDetached(outputDevice);
              }
            }
            midiOutputDevices.remove(usbDevice);
          }
          UsbDeviceConnection deviceConnection=deviceConnections.get(usbDevice);
          if (deviceConnection != null) {
            deviceConnection.close();
            deviceConnections.remove(usbDevice);
          }
          Log.d(Constants.TAG,"String_Node_Str" + usbDevice.getDeviceName() + "String_Node_Str");
          return null;
        }
      }
;
      task.execute(detachedDevice);
      return true;
    }
  }
);
  thread=new MidiDeviceConnectionWatchThread(usbManager,deviceAttachedListener,deviceDetachedHandler);
  thread.setName("String_Node_Str");
  thread.start();
}

Fixed version (ground truth):
/** 
 * Constructor
 * @param context the Context
 * @param usbManager the UsbManager
 * @param deviceAttachedListener the OnMidiDeviceAttachedListener
 */
public MidiDeviceConnectionWatcher(@NonNull Context context,@NonNull UsbManager usbManager,@NonNull OnMidiDeviceAttachedListener deviceAttachedListener,@NonNull final OnMidiDeviceDetachedListener deviceDetachedListener){
  this.context=context;
  this.usbManager=usbManager;
  isGranting=false;
  grantingDevice=null;
  this.deviceDetachedListener=deviceDetachedListener;
  deviceDetachedHandler=new Handler(new Handler.Callback(){
    @Override public boolean handleMessage(    Message message){
      AsyncTask<UsbDevice,Void,Void> task=new AsyncTask<UsbDevice,Void,Void>(){
        @Override protected Void doInBackground(        UsbDevice... params){
          if (params == null || params.length < 1) {
            return null;
          }
          UsbDevice usbDevice=params[0];
          onDeviceDetached(usbDevice);
          return null;
        }
      }
;
      UsbDevice detachedDevice=(UsbDevice)message.obj;
      task.execute(detachedDevice);
      return true;
    }
  }
);
  thread=new MidiDeviceConnectionWatchThread(usbManager,deviceAttachedListener,deviceDetachedHandler);
  thread.setName("String_Node_Str");
  thread.start();
}