Scene is copied before being queued to avoid concurrence

src/core/UBPersistenceManager.cpp

@@ -738,7 +738,11 @@ void UBPersistenceManager::persistDocumentScene(UBDocumentProxy* pDocumentProxy,
     if (pScene->isModified())
     {
         UBThumbnailAdaptor::persistScene(pDocumentProxy, pScene, pSceneIndex);
-        mWorker->saveScene(pDocumentProxy, pScene, pSceneIndex);
+        QTime time;
+        time.start();
+        UBGraphicsScene* copiedScene = pScene->sceneDeepCopy();
+        qDebug() << "time to duplicate scene " << time.elapsed() << " ms";
+        mWorker->saveScene(pDocumentProxy, copiedScene, pSceneIndex);
         pScene->setModified(false);
     }
 

src/core/UBPersistenceWorker.cpp

@@ -57,8 +57,11 @@ void UBPersistenceWorker::process()
     mSemaphore.acquire();
     do{
         PersistenceInformation info = saves.takeFirst();
-        if(info.action == WriteScene)
+        if(info.action == WriteScene){
             UBSvgSubsetAdaptor::persistScene(info.proxy, info.scene, info.sceneIndex);
+            delete info.scene;
+            info.scene = NULL;
+        }
         else{
             emit sceneLoaded(UBSvgSubsetAdaptor::loadSceneAsText(info.proxy,info.sceneIndex), info.proxy, info.sceneIndex);
         }

src/domain/UBGraphicsScene.cpp

@@ -665,14 +665,6 @@ void UBGraphicsScene::DisposeMagnifierQWidgets()
         magniferControlViewWidget = NULL;
     }
 
-    if(magniferDisplayViewWidget)
-    {
-        magniferDisplayViewWidget->hide();
-        magniferDisplayViewWidget->setParent(0);
-        delete magniferDisplayViewWidget;
-        magniferDisplayViewWidget = NULL;
-    }
-
     // some time have crash here on access to app (when call from destructor when close OpenBoard app)
     // so i just add try/catch section here
     try