This code in VCollectIterator::build_heap is possible to cause double free if cumu_iter->init() fails and returns early, becuase some LevelIterator* exists both in VCollectIterator::_children and cumu_iter::_children.
This code in VCollectIterator::build_heap is possible to cause double free if cumu_iter->init() fails and returns early, becuase some LevelIterator* exists both in VCollectIterator::_children and cumu_iter::_children.