Setting a replacment QScrollBar in QAbstractItemView causes loss of connection between View and Scrollbar

QAbstractItemVIew inherits from QAbstractScrollAreaPrivate and in

QAbstractItemViewPrivate::init()

connects actionTriggered, and valueChanged of both the horizontal and vertical scrollbars, with slots verticalScrollbarAction and horizontalScrollbarAction that for more complex views will call the QAbstractItemModel's fetchMore if necessary.

However, if you call QAbstractScrollArea::setVerticalScrollBar with a replacement scrollbar, those connections are not made and get stale.

It calls QAbstractScrollAreaPrivate::replaceScrollBar that connects valueChanged (and rangeChanged), to its own slots, but the connections of its subclass are not updated (and cannot be without adding a virtual method).

The same happens with setHorizontalScrollbar.