From 894c53ab2e75311965c9533bd453585f3c2c0134 Mon Sep 17 00:00:00 2001
From: gka <gka@opencascade.com>
Date: Mon, 29 May 2017 18:42:55 +0300
Subject: [PATCH] 0028797: Exceptrion is raised during reading attached STEP
 file.

Protection for null handle was added in the method RWStepVisual_RWPresentationStyleAssignment::ReadStep
---
 .../RWStepVisual_RWPresentationStyleAssignment.cxx         | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/RWStepVisual/RWStepVisual_RWPresentationStyleAssignment.cxx b/src/RWStepVisual/RWStepVisual_RWPresentationStyleAssignment.cxx
index 76a200f056..714957ce76 100644
--- a/src/RWStepVisual/RWStepVisual_RWPresentationStyleAssignment.cxx
+++ b/src/RWStepVisual/RWStepVisual_RWPresentationStyleAssignment.cxx
@@ -53,9 +53,12 @@ void RWStepVisual_RWPresentationStyleAssignment::ReadStep
       else {
         Handle(StepData_SelectMember) aMember;
         data->ReadMember(nsub1, i1, "null_style", ach, aMember);
-        Standard_CString anEnumText = aMember->EnumText();
         Handle(StepVisual_NullStyleMember) aNullStyle = new StepVisual_NullStyleMember();
-        aNullStyle->SetEnumText(0, anEnumText);
+        if(!aMember.IsNull())
+        {
+          Standard_CString anEnumText = aMember->EnumText();
+          aNullStyle->SetEnumText(0, anEnumText);
+        }
         aStylesItem.SetValue(aNullStyle);
       }
       aStyles->SetValue(i1,aStylesItem);
-- 
2.39.5