When the size adjust policy is QComboBox::AdjustToContents, the combobox
sizeHint was recalculated on dataChanged, rowsInserted, rowsRemoved,
and setModel, but not when the model was reset. This led to truncated
items in the combobox when models are filled asynchronously.
Task-number: QTBUG-5413
Change-Id: I3456c327d680dfffa58d6dcb26c79456c67b2a32
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@theqtcompany.com>
Reviewed-by: Marc Mutz <marc.mutz@kdab.com>