Program: 96848
Project: 96848
Buggy source:
public void flush(){
  if (sprites.size() == 0)   return;
  sortSprites();
  Batcher batcher=SilenceEngine.graphics.getBatcher();
  Texture originalTexture=Texture.CURRENT;
  Texture texture=sprites.get(indices.get(0)).getTexture();
  texture.bind();
  Vector2 temp=Vector2.REUSABLE_STACK.pop();
  batcher.begin(Primitive.TRIANGLES);
{
    for (    int i : indices) {
      Sprite sprite=sprites.get(i);
      Vector2 position=positions.get(i);
      Texture t=sprite.getTexture();
      if (t.getID() != texture.getID()) {
        batcher.end();
        texture=t;
        t.bind();
        batcher.begin(Primitive.TRIANGLES);
      }
      batcher.vertex(temp.set(-t.getWidth() / 2,-t.getHeight() / 2).rotateSelf(sprite.getRotation()).scaleSelf(sprite.getScaleX(),sprite.getScaleY()).addSelf(position).addSelf(t.getWidth() / 2,t.getHeight() / 2));
      batcher.texCoord(t.getMinU(),t.getMinV());
      batcher.color(sprite.getTint());
      batcher.vertex(temp.set(t.getWidth() / 2,-t.getHeight() / 2).rotateSelf(sprite.getRotation()).scaleSelf(sprite.getScaleX(),sprite.getScaleY()).addSelf(position).addSelf(t.getWidth() / 2,t.getHeight() / 2));
      batcher.texCoord(t.getMaxU(),t.getMinV());
      batcher.color(sprite.getTint());
      batcher.vertex(temp.set(-t.getWidth() / 2,t.getHeight() / 2).rotateSelf(sprite.getRotation()).scaleSelf(sprite.getScaleX(),sprite.getScaleY()).addSelf(position).addSelf(t.getWidth() / 2,t.getHeight() / 2));
      batcher.texCoord(t.getMinU(),t.getMaxV());
      batcher.color(sprite.getTint());
      batcher.vertex(temp.set(t.getWidth() / 2,-t.getHeight() / 2).rotateSelf(sprite.getRotation()).scaleSelf(sprite.getScaleX(),sprite.getScaleY()).addSelf(position).addSelf(t.getWidth() / 2,t.getHeight() / 2));
      batcher.texCoord(t.getMaxU(),t.getMinV());
      batcher.color(sprite.getTint());
      batcher.vertex(temp.set(t.getWidth() / 2,t.getHeight() / 2).rotateSelf(sprite.getRotation()).scaleSelf(sprite.getScaleX(),sprite.getScaleY()).addSelf(position).addSelf(t.getWidth() / 2,t.getHeight() / 2));
      batcher.texCoord(t.getMaxU(),t.getMaxV());
      batcher.color(sprite.getTint());
      batcher.vertex(temp.set(-t.getWidth() / 2,t.getHeight() / 2).rotateSelf(sprite.getRotation()).scaleSelf(sprite.getScaleX(),sprite.getScaleY()).addSelf(position).addSelf(t.getWidth() / 2,t.getHeight() / 2));
      batcher.texCoord(t.getMinU(),t.getMaxV());
      batcher.color(sprite.getTint());
    }
  }
  batcher.end();
  Vector2.REUSABLE_STACK.push(temp);
  sprites.clear();
  indices.clear();
  positions.forEach(Vector2.REUSABLE_STACK::push);
  positions.clear();
  originalTexture.bind();
}

Fixed version (ground truth):
public void flush(){
  if (sprites.size() == 0)   return;
  sortSprites();
  Batcher batcher=SilenceEngine.graphics.getBatcher();
  Texture originalTexture=Texture.CURRENT;
  Texture texture=sprites.get(indices.get(0)).getTexture();
  texture.bind();
  Vector2 temp=Vector2.REUSABLE_STACK.pop();
  batcher.begin(Primitive.TRIANGLES);
{
    for (    int i : indices) {
      Sprite sprite=sprites.get(i);
      Vector2 position=positions.get(i);
      Texture t=sprite.getTexture();
      if (t.getID() != texture.getID()) {
        batcher.end();
        texture=t;
        t.bind();
        batcher.begin(Primitive.TRIANGLES);
      }
      float width=t.getWidth() * sprite.getScaleX();
      float height=t.getHeight() * sprite.getScaleY();
      batcher.vertex(temp.set(-t.getWidth() / 2,-t.getHeight() / 2).rotateSelf(sprite.getRotation()).scaleSelf(sprite.getScaleX(),sprite.getScaleY()).addSelf(position).addSelf(width / 2,height / 2));
      batcher.texCoord(t.getMinU(),t.getMinV());
      batcher.color(sprite.getTint());
      batcher.vertex(temp.set(t.getWidth() / 2,-t.getHeight() / 2).rotateSelf(sprite.getRotation()).scaleSelf(sprite.getScaleX(),sprite.getScaleY()).addSelf(position).addSelf(width / 2,height / 2));
      batcher.texCoord(t.getMaxU(),t.getMinV());
      batcher.color(sprite.getTint());
      batcher.vertex(temp.set(-t.getWidth() / 2,t.getHeight() / 2).rotateSelf(sprite.getRotation()).scaleSelf(sprite.getScaleX(),sprite.getScaleY()).addSelf(position).addSelf(width / 2,height / 2));
      batcher.texCoord(t.getMinU(),t.getMaxV());
      batcher.color(sprite.getTint());
      batcher.vertex(temp.set(t.getWidth() / 2,-t.getHeight() / 2).rotateSelf(sprite.getRotation()).scaleSelf(sprite.getScaleX(),sprite.getScaleY()).addSelf(position).addSelf(width / 2,height / 2));
      batcher.texCoord(t.getMaxU(),t.getMinV());
      batcher.color(sprite.getTint());
      batcher.vertex(temp.set(t.getWidth() / 2,t.getHeight() / 2).rotateSelf(sprite.getRotation()).scaleSelf(sprite.getScaleX(),sprite.getScaleY()).addSelf(position).addSelf(width / 2,height / 2));
      batcher.texCoord(t.getMaxU(),t.getMaxV());
      batcher.color(sprite.getTint());
      batcher.vertex(temp.set(-t.getWidth() / 2,t.getHeight() / 2).rotateSelf(sprite.getRotation()).scaleSelf(sprite.getScaleX(),sprite.getScaleY()).addSelf(position).addSelf(width / 2,height / 2));
      batcher.texCoord(t.getMinU(),t.getMaxV());
      batcher.color(sprite.getTint());
    }
  }
  batcher.end();
  Vector2.REUSABLE_STACK.push(temp);
  sprites.clear();
  indices.clear();
  positions.forEach(Vector2.REUSABLE_STACK::push);
  positions.clear();
  originalTexture.bind();
}