When loading a scene that is about to be deleted, don't cache the previous and next scenes.

This prevents crashes that may occur when deleting multiple pages from a document.

src/core/UBPersistenceManager.cpp

@@ -483,7 +483,7 @@ void UBPersistenceManager::deleteDocumentScenes(UBDocumentProxy* proxy, const QL
 
     foreach(int index, compactedIndexes)
     {
-        UBGraphicsScene *scene = loadDocumentScene(proxy, index);
+        UBGraphicsScene *scene = loadDocumentScene(proxy, index, false);
         if (scene)
         {
             //scene is about to move into new document
@@ -727,7 +727,7 @@ void UBPersistenceManager::moveSceneToIndex(UBDocumentProxy* proxy, int source,
 }
 
 
-UBGraphicsScene* UBPersistenceManager::loadDocumentScene(UBDocumentProxy* proxy, int sceneIndex)
+UBGraphicsScene* UBPersistenceManager::loadDocumentScene(UBDocumentProxy* proxy, int sceneIndex, bool cacheNeighboringScenes)
 {
     UBGraphicsScene* scene = NULL;
 
@@ -740,11 +740,13 @@ UBGraphicsScene* UBPersistenceManager::loadDocumentScene(UBDocumentProxy* proxy,
             mSceneCache.insert(proxy, sceneIndex, scene);
     }
 
-    if(sceneIndex + 1 < proxy->pageCount() &&  !mSceneCache.contains(proxy, sceneIndex + 1))
-        mWorker->readScene(proxy,sceneIndex+1);
+    if (cacheNeighboringScenes) {
+        if(sceneIndex + 1 < proxy->pageCount() &&  !mSceneCache.contains(proxy, sceneIndex + 1))
+            mWorker->readScene(proxy,sceneIndex+1);
 
-    if(sceneIndex - 1 >= 0 &&  !mSceneCache.contains(proxy, sceneIndex - 1))
-        mWorker->readScene(proxy,sceneIndex-1);
+        if(sceneIndex - 1 >= 0 &&  !mSceneCache.contains(proxy, sceneIndex - 1))
+            mWorker->readScene(proxy,sceneIndex-1);
+    }
 
     return scene;
 }

src/core/UBPersistenceManager.h

@@ -85,7 +85,7 @@ class UBPersistenceManager : public QObject
 
         virtual void moveSceneToIndex(UBDocumentProxy* pDocumentProxy, int source, int target);
 
-        virtual UBGraphicsScene* loadDocumentScene(UBDocumentProxy* pDocumentProxy, int sceneIndex);
+        virtual UBGraphicsScene* loadDocumentScene(UBDocumentProxy* pDocumentProxy, int sceneIndex, bool cacheNeighboringScenes = true);
         UBGraphicsScene *getDocumentScene(UBDocumentProxy* pDocumentProxy, int sceneIndex) {return mSceneCache.value(pDocumentProxy, sceneIndex);}
 
         QList<QPointer<UBDocumentProxy> > documentProxies;