Program: 172510
Project: 172510
Buggy source:
/** 
 * Listening to events from VK longpoll server and call callbacks on events. You can override only necessary methods in callback to get necessary events.
 */
private void startListening(){
  LOG.info("String_Node_Str");
  while (on) {
    StringBuilder query=new StringBuilder();
    query.append("String_Node_Str").append(server).append("String_Node_Str").append(key).append("String_Node_Str").append(ts).append("String_Node_Str").append(wait).append("String_Node_Str").append(mode).append("String_Node_Str").append(version).append("String_Node_Str");
    JSONObject response=Connection.getRequestResponse(query.toString());
    if (response.has("String_Node_Str")) {
      int code=response.getInt("String_Node_Str");
      LOG.error("String_Node_Str",code);
switch (code) {
default :
{
          ts=response.has("String_Node_Str") ? response.getInt("String_Node_Str") : ts;
          setData(null,null,null,null,null,null);
          break;
        }
case 4:
{
        version=response.getInt("String_Node_Str");
        break;
      }
  }
}
 else {
  if (this.client.commands.size() > 0 || callbacks.size() > 0) {
    if (response.has("String_Node_Str") && response.has("String_Node_Str")) {
      Integer new_ts=response.getInt("String_Node_Str");
      Integer new_pts=response.has("String_Node_Str") ? response.getInt("String_Node_Str") : pts;
      JSONArray updates=response.getJSONArray("String_Node_Str");
      for (      Object currentUpdateObject : updates) {
        JSONArray currentUpdate=(JSONArray)currentUpdateObject;
        int updateType=currentUpdate.getInt(0);
switch (updateType) {
case 4:
{
            int messageFlags=currentUpdate.getInt(2);
            if ((messageFlags & 2) == 0) {
              Message message=new Message(access_token,currentUpdate.getInt(1),currentUpdate.getInt(2),currentUpdate.getInt(3),currentUpdate.getInt(4),currentUpdate.getString(5),(currentUpdate.length() > 6 ? (currentUpdate.get(6).toString().startsWith("String_Node_Str") ? new JSONObject(currentUpdate.get(6).toString()) : null) : null),currentUpdate.length() > 7 ? currentUpdate.getInt(7) : null);
              handleCommands(message);
              if (message.hasFwds() && callbacks.containsKey("String_Node_Str")) {
                ((OnMessageWithFwdsCallback)callbacks.get("String_Node_Str")).onMessage(message);
              }
switch (message.messageType()) {
case "String_Node_Str":
{
                  if (callbacks.containsKey("String_Node_Str")) {
                    ((OnVoiceMessageCallback)callbacks.get("String_Node_Str")).OnVoiceMessage(message);
                  }
 else {
                    if (callbacks.containsKey("String_Node_Str")) {
                      ((OnOtherMessagesCallback)callbacks.get("String_Node_Str")).onMessage(message);
                    }
                  }
                  break;
                }
case "String_Node_Str":
{
                if (callbacks.containsKey("String_Node_Str")) {
                  ((OnStickerMessageCallback)callbacks.get("String_Node_Str")).OnStickerMessage(message);
                }
 else {
                  if (callbacks.containsKey("String_Node_Str")) {
                    ((OnOtherMessagesCallback)callbacks.get("String_Node_Str")).onMessage(message);
                  }
                }
                break;
              }
case "String_Node_Str":
{
              if (callbacks.containsKey("String_Node_Str")) {
                ((OnGifMessageCallback)callbacks.get("String_Node_Str")).OnGifMessage(message);
              }
 else {
                if (callbacks.containsKey("String_Node_Str")) {
                  ((OnOtherMessagesCallback)callbacks.get("String_Node_Str")).onMessage(message);
                }
              }
              break;
            }
case "String_Node_Str":
{
            if (callbacks.containsKey("String_Node_Str")) {
              ((OnAudioMessageCallback)callbacks.get("String_Node_Str")).onAudioMessage(message);
            }
 else {
              if (callbacks.containsKey("String_Node_Str")) {
                ((OnOtherMessagesCallback)callbacks.get("String_Node_Str")).onMessage(message);
              }
            }
            break;
          }
case "String_Node_Str":
{
          if (callbacks.containsKey("String_Node_Str")) {
            ((OnVideoMessageCallback)callbacks.get("String_Node_Str")).onVideoMessage(message);
          }
 else {
            if (callbacks.containsKey("String_Node_Str")) {
              ((OnOtherMessagesCallback)callbacks.get("String_Node_Str")).onMessage(message);
            }
          }
          break;
        }
case "String_Node_Str":
{
        if (callbacks.containsKey("String_Node_Str")) {
          ((OnDocMessageCallback)callbacks.get("String_Node_Str")).OnDocMessage(message);
        }
 else {
          if (callbacks.containsKey("String_Node_Str")) {
            ((OnOtherMessagesCallback)callbacks.get("String_Node_Str")).onMessage(message);
          }
        }
        break;
      }
case "String_Node_Str":
{
      if (callbacks.containsKey("String_Node_Str")) {
        ((OnVoiceMessageCallback)callbacks.get("String_Node_Str")).OnVoiceMessage(message);
      }
 else {
        if (callbacks.containsKey("String_Node_Str")) {
          ((OnOtherMessagesCallback)callbacks.get("String_Node_Str")).onMessage(message);
        }
      }
      break;
    }
case "String_Node_Str":
{
    if (callbacks.containsKey("String_Node_Str")) {
      ((OnPhotoMessageCallback)callbacks.get("String_Node_Str")).onPhotoMessage(message);
    }
 else {
      if (callbacks.containsKey("String_Node_Str")) {
        ((OnOtherMessagesCallback)callbacks.get("String_Node_Str")).onMessage(message);
      }
    }
    break;
  }
case "String_Node_Str":
{
  if (callbacks.containsKey("String_Node_Str")) {
    ((OnLinkMessageCallback)callbacks.get("String_Node_Str")).OnLinkMessage(message);
  }
 else {
    if (callbacks.containsKey("String_Node_Str")) {
      ((OnOtherMessagesCallback)callbacks.get("String_Node_Str")).onMessage(message);
    }
  }
  break;
}
case "String_Node_Str":
{
if (callbacks.containsKey("String_Node_Str")) {
  ((OnSimpleTextMessageCallback)callbacks.get("String_Node_Str")).OnSimpleTextMessage(message);
}
 else {
  if (callbacks.containsKey("String_Node_Str")) {
    ((OnOtherMessagesCallback)callbacks.get("String_Node_Str")).onMessage(message);
  }
}
break;
}
}
if (callbacks.containsKey("String_Node_Str")) {
((OnMessageCallback)callbacks.get("String_Node_Str")).onMessage(message);
}
}
break;
}
case 61:
{
if (callbacks.containsKey("String_Node_Str")) {
((OnTypingCallback)callbacks.get("String_Node_Str")).OnTyping(currentUpdate.getInt(1));
}
break;
}
}
}
ts=new_ts;
}
 else {
LOG.error("String_Node_Str",response);
}
}
}
}
}

Fixed version (ground truth):
/** 
 * Listening to events from VK longpoll server and call callbacks on events. You can override only necessary methods in callback to get necessary events.
 */
private void startListening(){
  LOG.info("String_Node_Str");
  while (on) {
    StringBuilder query=new StringBuilder();
    query.append("String_Node_Str").append(server).append("String_Node_Str").append(key).append("String_Node_Str").append(ts).append("String_Node_Str").append(wait).append("String_Node_Str").append(mode).append("String_Node_Str").append(version).append("String_Node_Str");
    JSONObject response=Connection.getRequestResponse(query.toString());
    LOG.info("String_Node_Str",response);
    if (response.has("String_Node_Str")) {
      int code=response.getInt("String_Node_Str");
      LOG.error("String_Node_Str",code);
switch (code) {
default :
{
          if (response.has("String_Node_Str")) {
            ts=response.getInt("String_Node_Str");
          }
          setData(null,null,null,null,null);
          break;
        }
case 4:
{
        version=response.getInt("String_Node_Str");
        setData(null,null,null,null,null);
        break;
      }
  }
}
 else {
  if (response.has("String_Node_Str"))   ts=response.getInt("String_Node_Str");
  if (response.has("String_Node_Str"))   pts=response.getInt("String_Node_Str");
  if (this.updatesHandler.callbacksCount() > 0 || this.updatesHandler.commandsCount() > 0) {
    if (response.has("String_Node_Str") && response.has("String_Node_Str")) {
      this.updatesHandler.handle(response.getJSONArray("String_Node_Str"));
    }
 else {
      LOG.error("String_Node_Str",response);
    }
  }
}
}
}