As propertyobservers can execute arbitrarily complex code, they can also
modify the obsever list in multiple ways. To protect against list
corruption resulting from this, we introduce a protection scheme which
makes the list resilient against modification.
A detailed description of the scheme can be found as a comment in
QPropertyObserverPointer::notify.
Task-number: QTBUG-87153
Change-Id: I9bb49e457165ddc1e4c8bbdf3d3c9fbf5ff27e94
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Lars Knoll <lars.knoll@qt.io>