guard against missing parent layout

Change-Id: Ib08403edf805367c7392325fcfb66bc7ed4d6f6a
(cherry picked from commit 713d737b)

lotuswordpro/source/filter/lwpframelayout.cxx

@@ -186,8 +186,10 @@ void  LwpFrame::RegisterStyle(XFFrameStyle* pFrameStyle)
 */
  void LwpFrame::XFConvert(XFContentContainer* pCont)
  {
-     //parse the frame which anchor to page
+    // parse the frame which anchor to page
     LwpVirtualLayout* pParent = m_pLayout->GetParentLayout();
+    if (!pParent)
+        throw std::runtime_error("missing Parent Layout");
     if(pParent->IsPage()&& pParent->GetParentLayout()->IsPage())
     {
         //for mirror page, problems exist if the parent layout is header or footer layout,