fixes for discrete curves/surfaces

Mesh/SecondOrder.cpp

-// $Id: SecondOrder.cpp,v 1.30 2005-02-20 06:36:54 geuzaine Exp $
+// $Id: SecondOrder.cpp,v 1.31 2005-02-20 16:41:24 geuzaine Exp $
 //
 // Copyright (C) 1997-2005 C. Geuzaine, J.-F. Remacle
 //
@@ -60,9 +60,10 @@ Vertex *onCurve(Vertex * v1, Vertex * v2)
   int ok1 = 1, ok2 = 1;
   double u1 = 0., u2 = 0.;
 
-  if(!THEC->beg || !THEC->end)
+  if(!THEC->beg || !THEC->end){
     ok1 = ok2 = 0;
-
+  }
+  else{
     if(List_Nbr(v1->ListCurves) == 1){
       u1 = v1->u;
     }
@@ -95,6 +96,7 @@ Vertex *onCurve(Vertex * v1, Vertex * v2)
 	u2 == THEC->ubeg || u2 == THEC->uend)){
       ok1 = ok2 = 0;
     }
+  }
 
   if(ok1 && ok2){
     v = InterpolateCurve(THEC, 0.5 * (u1 + u2), 0);
@@ -122,7 +124,7 @@ Vertex *onSurface(Vertex * v1, Vertex * v2)
 
   if(!THES)
     return NULL;
-  if(THES->Typ == MSH_SURF_PLAN)
+  if(THES->Typ == MSH_SURF_PLAN || THES->Typ == MSH_SURF_DISCRETE)
     return NULL;
 
   XYZtoUV(THES, v1->Pos.X, v1->Pos.Y, v1->Pos.Z, &U1, &V1, 1.0);
@@ -144,7 +146,7 @@ Vertex *onSurface(Vertex * v1, Vertex * v2, Vertex * v3, Vertex * v4)
 
   if(!THES)
     return NULL;
-  if(THES->Typ == MSH_SURF_PLAN)
+  if(THES->Typ == MSH_SURF_PLAN || THES->Typ == MSH_SURF_DISCRETE)
     return NULL;
 
   XYZtoUV(THES, v1->Pos.X, v1->Pos.Y, v1->Pos.Z, &U1, &V1, 1.0);