Do not subtract from unsigned (size) values.
Amends d15d15efa2.
Change-Id: I9a8b09d3733b49ea646ae8a14caefcf5c908fad3
Reviewed-by: Eike Ziller <eike.ziller@qt.io>
This is more consistent with allData() and setAllData().
Adjust its only user.
Change-Id: Idd5cea3f37c6a84d052bd56a4a413a35d80289ad
Reviewed-by: David Schulz <david.schulz@qt.io>