0030995: Visualization - crash in angle computation between curvilinear faces

diff --git a/src/AIS/AIS.cxx b/src/AIS/AIS.cxx
index 60b6067de3c015025205a8e0f8c733c52ec466a7..f2b74f2e4544c1fb4f530f43ae7c3a33a496405c 100644 (file)
--- a/src/AIS/AIS.cxx
+++ b/src/AIS/AIS.cxx
@@ -1052,6 +1052,8 @@ Standard_Boolean AIS::InitAngleBetweenCurvilinearFaces (const TopoDS_Face&
   }
 
   aFirstLine = Handle(Geom_Line)::DownCast (aFirstSurf->UIso (aFirstU));
+  if (aFirstLine.IsNull())
+    return Standard_False;
 
   if (theSecondSurfType == AIS_KOS_Cylinder)
   {