Program: 141920
Project: 141920
Buggy source:
@Override public Controller setup(Bundle savedInstanceState,Controller controller){
  if (controller != null && controller instanceof ModelController) {
    @SuppressWarnings("String_Node_Str") ModelController<? extends Model> c=(ModelController<? extends Model>)controller;
    Model model=c.getModel();
    Session session=model.getSession();
    chatIconController=new ChatCounterController(session);
    if (savedInstanceState != null && savedInstanceState.containsKey("String_Node_Str")) {
      navigation=(NavigationController)savedInstanceState.getSerializable("String_Node_Str");
    }
 else {
      navigation=new NavigationController(new NavigationModel(session));
    }
    navigationScreen=DrawerScreen.create(navigation);
    getFragmentManager().beginTransaction().replace(R.id.navigation_drawer,navigationScreen).commit();
    navigationScreen.setUp(this,R.id.navigation_drawer,(DrawerLayout)findViewById(R.id.drawer_layout),R.drawable.ic_map_black_24dp);
    if (savedInstanceState != null && savedInstanceState.containsKey("String_Node_Str")) {
      stats=(StatsController)savedInstanceState.get("String_Node_Str");
    }
 else {
      stats=new StatsController(new StatsModel(session));
    }
    ViewScreen statsScreen=(ViewScreen)findViewById(R.id.game_stats_screen);
    statsScreen.display(stats,this);
  }
 else {
    Logger.log("String_Node_Str","String_Node_Str" + controller + "String_Node_Str");
  }
  return controller;
}

Fixed version (ground truth):
@Override public Controller setup(Bundle savedInstanceState,Controller controller){
  Session session=null;
  if (controller != null && controller instanceof ModelController) {
    @SuppressWarnings("String_Node_Str") ModelController<? extends Model> c=(ModelController<? extends Model>)controller;
    Model model=c.getModel();
    session=model.getSession();
  }
  if (savedInstanceState != null && savedInstanceState.containsKey("String_Node_Str")) {
    chatIconController=(ChatCounterController)savedInstanceState.getSerializable("String_Node_Str");
  }
 else   if (session != null) {
    chatIconController=new ChatCounterController(session);
  }
 else {
    Logger.log("String_Node_Str","String_Node_Str" + controller + "String_Node_Str");
  }
  if (savedInstanceState != null && savedInstanceState.containsKey("String_Node_Str")) {
    navigation=(NavigationController)savedInstanceState.getSerializable("String_Node_Str");
  }
 else   if (session != null) {
    navigation=new NavigationController(new NavigationModel(session));
  }
 else {
    Logger.log("String_Node_Str","String_Node_Str" + controller + "String_Node_Str");
  }
  if (navigation != null) {
    navigationScreen=DrawerScreen.create(navigation);
    getFragmentManager().beginTransaction().replace(R.id.navigation_drawer,navigationScreen).commit();
    navigationScreen.setUp(this,R.id.navigation_drawer,(DrawerLayout)findViewById(R.id.drawer_layout),R.drawable.ic_map_black_24dp);
  }
  if (savedInstanceState != null && savedInstanceState.containsKey("String_Node_Str")) {
    stats=(StatsController)savedInstanceState.get("String_Node_Str");
  }
 else   if (session != null) {
    stats=new StatsController(new StatsModel(session));
  }
 else {
    Logger.log("String_Node_Str","String_Node_Str" + controller + "String_Node_Str");
  }
  if (stats != null) {
    ViewScreen statsScreen=(ViewScreen)findViewById(R.id.game_stats_screen);
    statsScreen.display(stats,this);
  }
  return controller;
}