Fix crash when moving items during asynchronous creation

In complicated cases where the model moves rows around while
the view is running slow (perhaps during high CPU load),
there were cases when Repeater would call
movedItem->stackBefore(deleteableItem), but deleteable items
can be null, so there was often an error
QQuickItem::stackBefore: Cannot stack before 0x0, which must be a sibling
and occasionally a crash.  Now we check both the callee and the
parameter to stackBefore to make sure neither of them are null.

Task-number: QTBUG-54859
Change-Id: I45a8b2939c16b9bbe3a802ddd348dc55f51061a7
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>

0 files changed, 0 insertions, 0 deletions