[Crash Fix:] Startup crash without restoring session

src/app/qupzilla.h

@@ -96,8 +96,8 @@ public:
     void showInspector();
     void setBackground(QColor textColor);
 
-    inline WebView* weView() const { return qobject_cast<WebTab*>(m_tabWidget->widget(m_tabWidget->currentIndex()))->view(); }
-    inline WebView* weView(int index) const { return qobject_cast<WebTab*>(m_tabWidget->widget(index))->view(); }
+    inline WebView* weView() const { WebTab* webTab = qobject_cast<WebTab*>(m_tabWidget->widget(m_tabWidget->currentIndex())); if (!webTab) return 0; return webTab->view(); }
+    inline WebView* weView(int index) const { WebTab* webTab = qobject_cast<WebTab*>(m_tabWidget->widget(index)); if (!webTab) return 0; return webTab->view(); }
     inline LocationBar* locationBar(){ return m_locationBar; }
     inline TabWidget* tabWidget(){ return m_tabWidget; }
     inline BookmarksToolbar* bookmarksToolbar(){ return m_bookmarksToolbar; }

src/webview/tabwidget.h

@@ -68,8 +68,8 @@ private slots:
     void actionChangeIndex();
 
 private:
-    inline WebView* weView() { return qobject_cast<WebTab*>(widget(currentIndex()))->view(); }
-    inline WebView* weView(int index) { return qobject_cast<WebTab*>(widget(index))->view(); }
+    inline WebView* weView() { WebTab* webTab = qobject_cast<WebTab*>(widget(currentIndex())); if (!webTab) return 0; return webTab->view(); }
+    inline WebView* weView(int index) { WebTab* webTab = qobject_cast<WebTab*>(widget(index)); if (!webTab) return 0; return webTab->view(); }
 
     bool m_hideCloseButtonWithOneTab;
     bool m_hideTabBarWithOneTab;