Program: 86559
Project: 86559
Buggy source:
public void render(Canvas canvas,Camera camera,float alpha){
  Vector2f camPos=camera.getRenderPosition(alpha);
  Rectangle viewport=camera.getViewPort();
  this.currentFrameViewport.setBounds(viewport);
  this.mapOffset=camPos;
  int vx=viewport.getX();
  int vy=viewport.getY();
  int pixelX=0;
  int pixelY=0;
  int indexX=0;
  int indexY=0;
  int toIndex_x=0, toIndex_y=0;
  int camPosX=(int)(camPos.x);
  int camPosY=(int)(camPos.y);
  int tileOffset_x=-(camPosX % this.tileWidth);
  toIndex_x=(tileOffset_x + camPosX) / this.tileWidth;
  int tileOffset_y=-(camPosY % this.tileHeight);
  toIndex_y=(tileOffset_y + camPosY) / this.tileHeight;
  renderBackground(canvas,camera);
  indexY=toIndex_y;
  for (pixelY=tileOffset_y; pixelY < viewport.getHeight() && indexY < this.maxY; pixelY+=this.tileHeight, indexY++) {
    for (pixelX=tileOffset_x, indexX=toIndex_x; pixelX < viewport.getWidth() && indexX < this.maxX; pixelX+=this.tileWidth, indexX++) {
      if ((indexY >= 0 && indexX >= 0) && (indexY < this.maxY && indexX < this.maxX)) {
        for (int i=0; i < this.backgroundLayers.length; i++) {
          Layer layer=this.backgroundLayers[i];
          if (layer == null) {
            continue;
          }
          if (layer.isPropertyLayer()) {
            continue;
          }
          Tile tile=layer.getRow(indexY)[indexX];
          if (tile != null) {
            tile.setRenderingPosition(pixelX + vx,pixelY + vy);
            tile.render(canvas,camera,alpha);
          }
        }
      }
    }
  }
  renderMapObjects(canvas,camera,alpha);
}

Fixed version (ground truth):
public void render(Canvas canvas,Camera camera,float alpha){
  Vector2f camPos=camera.getRenderPosition(alpha);
  Rectangle viewport=camera.getViewPort();
  this.currentFrameViewport.setBounds(viewport);
  this.mapOffset=camPos;
  int vx=viewport.getX();
  int vy=viewport.getY();
  int pixelX=0;
  int pixelY=0;
  int indexX=0;
  int indexY=0;
  int toIndex_x=0, toIndex_y=0;
  int camPosX=(int)(camPos.x);
  int camPosY=(int)(camPos.y);
  int tileOffset_x=-(camPosX % this.tileWidth);
  toIndex_x=(tileOffset_x + camPosX) / this.tileWidth;
  int tileOffset_y=-(camPosY % this.tileHeight);
  toIndex_y=(tileOffset_y + camPosY) / this.tileHeight;
  renderBackground(canvas,camera);
  indexY=toIndex_y;
  for (pixelY=tileOffset_y; pixelY < viewport.getHeight() && indexY < this.maxY; pixelY+=this.tileHeight, indexY++) {
    for (pixelX=tileOffset_x, indexX=toIndex_x; pixelX < viewport.getWidth() && indexX < this.maxX; pixelX+=this.tileWidth, indexX++) {
      if ((indexY >= 0 && indexX >= 0) && (indexY < this.maxY && indexX < this.maxX)) {
        for (int i=0; i < this.backgroundLayers.length; i++) {
          Layer layer=this.backgroundLayers[i];
          if (layer == null) {
            continue;
          }
          if (layer.isPropertyLayer()) {
            continue;
          }
          Tile tile=layer.getRow(indexY)[indexX];
          if (tile != null) {
            tile.setRenderingPosition(pixelX + vx,pixelY + vy);
            tile.render(canvas,camera,alpha);
          }
        }
      }
    }
  }
  renderMapObjects(canvas,camera,alpha,this.backgroundMapObjects);
}