Program: 86867
Project: 86867
Buggy source:
public void applyGameUpdate(GameUpdateMessage msg){
  NetGameUpdate netUpdate=msg.netUpdate;
  gameClock=netUpdate.time;
  if (netUpdate.entities != null) {
    int size=netUpdate.entities.length;
    for (int i=0; i < size; i++) {
      NetEntity netEnt=netUpdate.entities[i];
      if (netEnt != null) {
        if (entities.containsEntity(netEnt.id)) {
          ClientEntity ent=entities.getEntity(netEnt.id);
          if (Type.fromNet(netEnt.type) == ent.getType()) {
            ent.updateState(netEnt,gameClock);
          }
 else {
            removeEntity(i);
            createEntity(netEnt);
          }
        }
 else {
          createEntity(netEnt);
        }
      }
 else {
        if (i < SeventhConstants.MAX_PERSISTANT_ENTITIES) {
          if (netUpdate.deadPersistantEntities.getBit(i)) {
            removeEntity(i);
          }
        }
 else {
          removeEntity(i);
        }
      }
    }
  }
  if (netUpdate.sounds != null) {
    int size=netUpdate.sounds.length;
    for (int i=0; i < size; i++) {
      NetSound snd=netUpdate.sounds[i];
      if (snd != null) {
        Sounds.playSound(snd,snd.posX,snd.posY);
      }
    }
  }
  if (netUpdate.spectatingPlayerId > -1) {
    int previousSpec=localPlayer.getSpectatingPlayerId();
    localPlayer.setSpectatingPlayerId(netUpdate.spectatingPlayerId);
    if (previousSpec != netUpdate.spectatingPlayerId) {
      ClientEntity ent=this.entities.getEntity(netUpdate.spectatingPlayerId);
      if (ent != null) {
        camera.centerAroundNow(ent.getCenterPos());
      }
    }
  }
 else {
    localPlayer.setSpectatingPlayerId(Entity.INVALID_ENTITY_ID);
  }
}

Fixed version (ground truth):
public void applyGameUpdate(GameUpdateMessage msg){
  NetGameUpdate netUpdate=msg.netUpdate;
  gameClock=netUpdate.time;
  if (netUpdate.entities != null) {
    int size=netUpdate.entities.length;
    for (int i=0; i < size; i++) {
      NetEntity netEnt=netUpdate.entities[i];
      if (netEnt != null) {
        if (entities.containsEntity(netEnt.id)) {
          ClientEntity ent=entities.getEntity(netEnt.id);
          if (Type.fromNet(netEnt.type) == ent.getType()) {
            ent.updateState(netEnt,gameClock);
          }
 else {
            removeEntity(i);
            createEntity(netEnt);
          }
        }
 else {
          createEntity(netEnt);
        }
      }
 else {
        if (i < SeventhConstants.MAX_PERSISTANT_ENTITIES) {
          if (netUpdate.deadPersistantEntities.getBit(i)) {
            removeEntity(i);
          }
        }
 else {
          removeEntity(i);
        }
      }
    }
  }
  if (netUpdate.sounds != null) {
    int size=netUpdate.numberOfSounds;
    for (int i=0; i < size; i++) {
      NetSound snd=netUpdate.sounds[i];
      if (snd != null) {
        Sounds.playSound(snd,snd.posX,snd.posY);
      }
    }
  }
  if (netUpdate.spectatingPlayerId > -1) {
    int previousSpec=localPlayer.getSpectatingPlayerId();
    localPlayer.setSpectatingPlayerId(netUpdate.spectatingPlayerId);
    if (previousSpec != netUpdate.spectatingPlayerId) {
      ClientEntity ent=this.entities.getEntity(netUpdate.spectatingPlayerId);
      if (ent != null) {
        camera.centerAroundNow(ent.getCenterPos());
      }
    }
  }
 else {
    localPlayer.setSpectatingPlayerId(Entity.INVALID_ENTITY_ID);
  }
}