From 67bd61d4d375b4e71199eb28269706b9a6664c60 Mon Sep 17 00:00:00 2001
From: Pasukhin Dmitry <dpasukhi@opencascade.com>
Date: Fri, 14 Feb 2025 14:13:53 +0100
Subject: [PATCH] Data Exchange - IGES Import Degenerated BSpline crash #368

Degenerated bspline leads to null dereference
Fix BSpline curve check and improve exception handling in TransferBSplineCurve
---
 src/IGESToBRep/IGESToBRep_BasicCurve.cxx | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/IGESToBRep/IGESToBRep_BasicCurve.cxx b/src/IGESToBRep/IGESToBRep_BasicCurve.cxx
index 70aacdd371..e071bfc7d4 100644
--- a/src/IGESToBRep/IGESToBRep_BasicCurve.cxx
+++ b/src/IGESToBRep/IGESToBRep_BasicCurve.cxx
@@ -1130,9 +1130,11 @@ Handle(Geom_Curve) IGESToBRep_BasicCurve::TransferBSplineCurve(
     //: 5    BSplineC = new Geom_BSplineCurve(Poles, Weight, Knot, Mult, Degree);
   }
 
-  // sln 29.12.2001 OCC90 : If curve can not be created do nothing
-  if (!checkBSplineCurve(this, start, Knot, Weight))
+  // If curve can not be created do nothing
+  if (Poles.Size() < 2 || !checkBSplineCurve(this, start, Knot, Weight))
+  {
     return BSplineRes;
+  }
 
   {
     try
@@ -1151,6 +1153,7 @@ Handle(Geom_Curve) IGESToBRep_BasicCurve::TransferBSplineCurve(
       anException.Print(std::cout);
 #endif
       (void)anException;
+      return BSplineRes;
     }
   }