Attempt to fix crash in the ticket 515.

src/gui/UBLibNavigatorWidget.cpp

@@ -126,11 +126,14 @@ void UBLibNavigatorWidget::onNavigbarUpate(UBLibElement *pElem)
  */
 void UBLibNavigatorWidget::onPathItemClicked(UBChainedLibElement *elem)
 {
+	if (!this->libraryWidget()->isLoadingLibraryItems())
+	{
 		// If this element has some subelement, remove them
 		removeNextChainedElements(elem);
 
 		// The refresh the view
 		mLibWidget->setCurrentElemsAndRefresh(elem);
+	}
 }
 
 /**

src/gui/UBLibPathViewer.cpp

@@ -405,9 +405,10 @@ void UBPathScene::mouseReleaseEvent(QGraphicsSceneMouseEvent *event)
             if(NULL != pView)
             {
                 int iClickedItem = pView->widgetAt(event->scenePos());
-                if(-1 != iClickedItem)
+				QGraphicsLayout* wgtLayout = pGWidget->layout();
+                if(iClickedItem != -1 && wgtLayout != NULL)
                 {
-                    QGraphicsWidget* pFolderW = dynamic_cast<QGraphicsWidget*>(pGWidget->layout()->itemAt(iClickedItem));
+					QGraphicsWidget* pFolderW = dynamic_cast<QGraphicsWidget*>(wgtLayout->itemAt(iClickedItem));
                     if(NULL != pFolderW)
                     {
                         UBChainedLibElement* chElem = mMapWidgetToChainedElem[pFolderW];

src/gui/UBLibraryWidget.cpp

@@ -43,6 +43,7 @@ UBLibraryWidget::UBLibraryWidget(QWidget *parent, const char *name):UBThumbnailW
     , mpCrntDir(NULL)
     , mpCrntElem(NULL)
     , mpTmpElem(NULL)
+	, mLoadingLibraryItems(false)
 {
     setObjectName(name);
     setSpacing(5);
@@ -147,6 +148,7 @@ void UBLibraryWidget::onItemClicked(QGraphicsItem *item, int index)
     Q_UNUSED(index);
     if(NULL != item)
     {
+        mLoadingLibraryItems = true;
 		int iItem = mGraphicItems.indexOf(item);
         if(0 <= iItem)
         {
@@ -183,6 +185,7 @@ void UBLibraryWidget::onItemClicked(QGraphicsItem *item, int index)
             }
             emit itemClicked();
         }
+		mLoadingLibraryItems = false;
     }
 }
 

src/gui/UBLibraryWidget.h

@@ -48,6 +48,7 @@ public:
     void init();
 
     UBLibraryController* libraryController() {return mLibraryController;}
+	bool isLoadingLibraryItems() const { return mLoadingLibraryItems; }
 
 public slots:
     void onRefreshCurrentFolder();
@@ -92,7 +93,7 @@ private:
     QList<UBLibElement*> mCurrentElems;
     QList<UBLibElement*> mOrigCurrentElems;
     QList<QGraphicsItem*> mItems;
-
+	bool mLoadingLibraryItems;
 };
 
 class UBNewFolderDlg : public QDialog