ChangeArbiter/SceneChange: use id as change subject

Instead of having a QNode* or QObservable as the subject of a change, we use
it's unique NodeId instead. That will prevent the ChangeArbiter from trying to
distribute changes by looking at a QNode/QObservable id when the
QNode/QObservable might have been destroyed in the meantime.

Change-Id: Ia419d5b841434fd65522c8c65de552089cfe97cf
Task-number: QTBUG-44628
Reviewed-by: Laszlo Agocs <laszlo.agocs@theqtcompany.com>
Reviewed-by: Sean Harmer <sean.harmer@kdab.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/src/core/qscenechange_p.h b/src/core/qscenechange_p.h
index 40748e444..b903b1035 100644
--- a/src/core/qscenechange_p.h
+++ b/src/core/qscenechange_p.h
@@ -44,6 +44,7 @@ QT_BEGIN_NAMESPACE
 namespace Qt3D {
 
 class QSceneChange;
+class QNodeId;
 
 class QSceneChangePrivate
 {
@@ -55,7 +56,7 @@ public :
 
     QSceneChange *q_ptr;
 
-    QSceneChange::SubjectUnion m_subject;
+    QNodeId m_subjectId;
     QSceneChange::ObservableType m_subjectType;
     ChangeFlag m_type;
     QSceneChange::Priority m_priority;