new workaround for disconnected thumbnail views... to change ASAP

src/board/UBBoardController.cpp

@@ -1567,11 +1567,19 @@ void UBBoardController::setActiveDocumentScene(UBDocumentProxy* pDocumentProxy,
     updateBackgroundActionsState(mActiveScene->isDarkBackground(), mActiveScene->pageBackground());
 
     if(documentChange)
+    {
         UBGraphicsTextItem::lastUsedTextColor = QColor();
+    }
 
     if (sceneChange)
+    {
+        //should not be necessary, but no more time to investigate on it for the moment :
+        //for some reason, certain thumbnail views are not updating except if we load the document twice....
+        //the only workaroud I found for the moment..
+        emit initThumbnailsRequired(this);
         emit activeSceneChanged();
     }
+}
 
 
 void UBBoardController::moveSceneToIndex(int source, int target)

src/gui/UBBoardThumbnailsView.cpp

@@ -127,7 +127,13 @@ void UBBoardThumbnailsView::addThumbnail(UBDocumentContainer* source, int i)
 
 void UBBoardThumbnailsView::clearThumbnails()
 {
-    qDeleteAll(mThumbnails);
+    for(int i = 0; i < mThumbnails.size(); i++)
+    {
+        scene()->removeItem(mThumbnails.at(i)->pageNumber());
+        scene()->removeItem(mThumbnails.at(i));
+        mThumbnails.at(i)->deleteLater();
+    }
+
     mThumbnails.clear();
 }