The transaction implementation in setItemData tries to make a copy of the original item, then writes to that copy, and swaps the original item with the modified copy only if all changes were written successfully. The write-operation happens on a pointer to that item via QMetaProperty APIs. So for non-copyable items, we return a pointer to the origin. If the item is owned by a unique_ptr, then we cannot make copies, so we write to the pointer to the original item. Use our pointerTo helper to get that pointer in all cases to unwrap unique_ptr. Otherwise, we'd pass the address of the unique_ptr to the QMetaProperty API and crash. Add test coverage, and enable SetItemData tests for listOfObjects as well. Pick-to: 6.10 Change-Id: Ia23c22f60171aacea64259a97b64ec7278db35a0 Reviewed-by: Artem Dyomin <artem.dyomin@qt.io>