Resolves fdo#54155: Crash when playing with a Group inside a Group

Change-Id: I89c80fca1cdc8bc88172eaf8057141d5e42a06dc

sw/source/core/frmedt/feshview.cxx

@@ -1136,7 +1136,7 @@ bool SwFEShell::ShouldObjectBeSelected(const Point& rPt)
 
             // Don't select header / footer objects in body edition and vice-versa
             SwContact* pContact = static_cast<SwContact*>(pObj->GetUserCall());
-            if ( !pContact->ObjAnchoredAtPage() )
+            if (pContact && !pContact->ObjAnchoredAtPage() )
             {
                 const SwPosition& rPos = pContact->GetCntntAnchor();
                 bool bInHdrFtr = GetDoc()->IsInHeaderFooter( rPos.nNode );