From ea7ffc28023772caf719d8e32320b5fdd0fa1fb9 Mon Sep 17 00:00:00 2001
From: gka <gka@opencascade.com>
Date: Mon, 21 May 2018 16:09:28 +0300
Subject: [PATCH] 0029784: Crash at STEP file reading with enabled sub-shapes

In the method STEPCAFControl_Reader::ExpandShell protection for case when entity ""Connected_Face_Set" contains not only "FACE" entities ( for example "VERTEX_POINT" entities) was added.
---
 src/STEPCAFControl/STEPCAFControl_Reader.cxx | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/STEPCAFControl/STEPCAFControl_Reader.cxx b/src/STEPCAFControl/STEPCAFControl_Reader.cxx
index 75fd04b0df..e3b8c9997b 100644
--- a/src/STEPCAFControl/STEPCAFControl_Reader.cxx
+++ b/src/STEPCAFControl/STEPCAFControl_Reader.cxx
@@ -4580,6 +4580,8 @@ void STEPCAFControl_Reader::ExpandShell(const Handle(StepShape_ConnectedFaceSet)
   for ( Standard_Integer f = aFaces->Lower(); f <= aFaces->Upper(); ++f )
   {
     const Handle(StepShape_Face)& aFace = aFaces->Value(f);
+    if (aFace.IsNull())
+      continue;
 
     // Record CAF data
     SettleShapeData(aFace, RootLab, ShapeTool, TP);