From 476ed21f1b90ed3b50685ddc328eecc4a917d2d8 Mon Sep 17 00:00:00 2001
From: kgv <kgv@opencascade.com>
Date: Tue, 27 Mar 2012 11:58:50 +0400
Subject: [PATCH] 0022523: DRAWEXE randomly crashed on smooth navigation in
 3D-Viewer

Check vector modulus to avoid possible exceptions.
---
 src/NIS/NIS_View.cxx | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/NIS/NIS_View.cxx b/src/NIS/NIS_View.cxx
index 7c4d644798..45f84111ee 100755
--- a/src/NIS/NIS_View.cxx
+++ b/src/NIS/NIS_View.cxx
@@ -550,6 +550,11 @@ void  NIS_View::Select (const NCollection_List<gp_XY> &thePolygon,
 
   // Compute transformation.
   const gp_XYZ anXdir (gp_XYZ(anX, anY, aZ) - anEye.XYZ());
+  if (anXdir.Modulus() <= gp::Resolution())
+  {
+    return;
+  }
+
   const gp_Ax3 anAx3 (anEye, aProj, anXdir);
   gp_Trsf aTrf;
   aTrf.SetTransformation (anAx3);