message: Don't call QObject::connect for a NULL model
diff: @@ -79,12 +79,16 @@ void RDHeaderView::setModel(QAbstractItemModel *model)
  QHeaderView::setModel(model);
  + if(model)
  + {
  QObject::connect(model, &QAbstractItemModel::headerDataChanged, this,
  &RDHeaderView::headerDataChanged);
  - QObject::connect(model, &QAbstractItemModel::columnsInserted, this, &RDHeaderView::columnsInserted);
  + QObject::connect(model, &QAbstractItemModel::columnsInserted, this,
  + &RDHeaderView::columnsInserted);
  QObject::connect(model, &QAbstractItemModel::rowsInserted, this, &RDHeaderView::rowsChanged);
  QObject::connect(model, &QAbstractItemModel::rowsRemoved, this, &RDHeaderView::rowsChanged);
  }
  +}
  void RDHeaderView::reset()
  {
  