coding

iOSClient/Viewer/NCViewerPDF/NCViewerPDF.swift

@@ -241,3 +241,10 @@ class NCViewerPDF: UIViewController, NCViewerPDFSearchDelegate {
         pdfView.go(to: pdfSelection)
     }
 }
+
+extension NCViewerPDF : UINavigationControllerDelegate {
+
+    override func willMove(toParent parent: UIViewController?) {
+        super.willMove(toParent: parent)
+     }
+}