Program: 96921
Project: 96921
Buggy source:
/** 
 * Starts the game. Initiates the game life-cycle and starts the main game-loop.
 */
public void start(){
  instance=this;
  SilenceEngine.getInstance().init();
  Logger.log("String_Node_Str");
  init();
  Runtime.getRuntime().gc();
  Logger.log("String_Node_Str");
  final double frameTime=1.0 / targetUPS;
  final double maxFrameSkips=10;
  double currentTime;
  double previousTime;
  double elapsed;
  double lag=0;
  double lastUPSUpdate=0;
  double lastFPSUpdate=0;
  int updatesProcessed=0;
  int framesProcessed=0;
  int skippedFrames=0;
  previousTime=TimeUtils.currentTime();
  running=true;
  while (true) {
    SilenceEngine.getInstance().beginFrame();
    if (Display.isCloseRequested() || !isRunning())     break;
    if (Display.wasResized()) {
      GL3Context.viewport(0,0,Display.getWidth(),Display.getHeight());
      Graphics2D.getInstance().getCamera().initProjection(Display.getWidth(),Display.getHeight());
      resize();
      if (gameState != null)       gameState.resize();
    }
    currentTime=TimeUtils.currentTime();
    elapsed=currentTime - previousTime;
    lag+=elapsed;
    while (lag > frameTime && skippedFrames < maxFrameSkips) {
      SilenceEngine.input.beginFrame();
{
        update((float)frameTime);
        if (gameState != null)         gameState.update((float)frameTime);
        GameTimer.updateTimers((float)frameTime);
      }
      SilenceEngine.input.endFrame();
      updatesProcessed++;
      lag-=frameTime;
      skippedFrames++;
      if (currentTime - lastUPSUpdate >= 1000) {
        ups=updatesProcessed;
        updatesProcessed=0;
        lastUPSUpdate=currentTime;
      }
    }
    float lagOffset=(float)(lag / frameTime);
    render(lagOffset,batcher);
    if (gameState != null)     gameState.render(lagOffset,batcher);
    framesProcessed++;
    if (currentTime - lastFPSUpdate >= 1000) {
      fps=framesProcessed;
      framesProcessed=0;
      lastFPSUpdate=currentTime;
    }
    SilenceEngine.getInstance().endFrame();
    Display.update();
    skippedFrames=0;
    previousTime=currentTime;
  }
  Game.end();
}

Fixed version (ground truth):
/** 
 * Starts the game. Initiates the game life-cycle and starts the main game-loop.
 */
public void start(){
  instance=this;
  SilenceEngine.getInstance().init();
  Logger.log("String_Node_Str");
  init();
  Runtime.getRuntime().gc();
  Logger.log("String_Node_Str");
  final double frameTime=1.0 / targetUPS;
  final double maxFrameSkips=10;
  double currentTime;
  double previousTime;
  double elapsed;
  double lag=0;
  double lastUPSUpdate=0;
  double lastFPSUpdate=0;
  int updatesProcessed=0;
  int framesProcessed=0;
  int skippedFrames=0;
  previousTime=TimeUtils.currentTime();
  running=true;
  while (true) {
    SilenceEngine.getInstance().beginFrame();
    if (Display.isCloseRequested() || !isRunning()) {
      Game.end();
      break;
    }
    if (Display.wasResized()) {
      GL3Context.viewport(0,0,Display.getWidth(),Display.getHeight());
      Graphics2D.getInstance().getCamera().initProjection(Display.getWidth(),Display.getHeight());
      resize();
      if (gameState != null)       gameState.resize();
    }
    currentTime=TimeUtils.currentTime();
    elapsed=currentTime - previousTime;
    lag+=elapsed;
    while (lag > frameTime && skippedFrames < maxFrameSkips) {
      SilenceEngine.input.beginFrame();
{
        update((float)frameTime);
        if (gameState != null)         gameState.update((float)frameTime);
        GameTimer.updateTimers((float)frameTime);
      }
      SilenceEngine.input.endFrame();
      updatesProcessed++;
      lag-=frameTime;
      skippedFrames++;
      if (currentTime - lastUPSUpdate >= 1000) {
        ups=updatesProcessed;
        updatesProcessed=0;
        lastUPSUpdate=currentTime;
      }
    }
    float lagOffset=(float)(lag / frameTime);
    render(lagOffset,batcher);
    if (gameState != null)     gameState.render(lagOffset,batcher);
    framesProcessed++;
    if (currentTime - lastFPSUpdate >= 1000) {
      fps=framesProcessed;
      framesProcessed=0;
      lastFPSUpdate=currentTime;
    }
    SilenceEngine.getInstance().endFrame();
    Display.update();
    skippedFrames=0;
    previousTime=currentTime;
  }
  Game.end();
}