Repeater does not refresh role names on model reset

When a custom QAbstractItemModel is used within QML as a model of Repeater, the Repeater only exposes to delegates those role names available at the time when the first delegate item is created.

The exposed role names are not refreshed when the model is reset (after having called QAbstractItemModel::beginResetModel() and QAbstractItemModel::endResetModel(), although the documentation for these methods states a view should do so.

The only way to have Repeater refresh the roles names is to re-assign the model, i.e. first assign "undefined" to the "model" property, and then assign the model again.