The convenience functions setBackground(), setForeground() and
setSizeHint() a default constructed value as 'reset'. This means a
default constructed QBrush or QSize is returned in the data() function
which leads to an unexpected background or forground color or size hint.
Therefore check if the passed value is a default constructed value and
set an empty QVariant instead which.
[ChangeLog][QtWidgets][ItemViews] The convenience views
QList/Table/TreeWidgetItem now treat a default constructed QBrush or
QSize as an empty QVariant which allows to reset the values set to it's
default values.
Task-number: QTBUG-76423
Change-Id: I840570bbad3e5fd8c5b4b58903b4fd0066dbdeb7
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@qt.io>
96c27eb710