From afccf69cb76e13b939a754c3acbe603ed7153fed Mon Sep 17 00:00:00 2001
From: Pasukhin Dmitry <dpasukhi@opencascade.com>
Date: Sat, 16 Aug 2025 09:24:21 +0100
Subject: [PATCH] Data Exchange, STP - Crash on empty list (#671)

Added condition to always allocate an array in case of empty list
---
 .../TKDESTEP/StepData/StepData_StepReaderData.cxx        | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/src/DataExchange/TKDESTEP/StepData/StepData_StepReaderData.cxx b/src/DataExchange/TKDESTEP/StepData/StepData_StepReaderData.cxx
index 6d55f967c0..8bdb3b113c 100644
--- a/src/DataExchange/TKDESTEP/StepData/StepData_StepReaderData.cxx
+++ b/src/DataExchange/TKDESTEP/StepData/StepData_StepReaderData.cxx
@@ -688,7 +688,14 @@ Standard_Boolean StepData_StepReaderData::ReadSubList(const Standard_Integer   n
   numsub = SubListNumber(num, nump, Standard_False);
   if (numsub > 0)
   {
-    return (NbParams(numsub) > 0);
+    const Standard_Integer aNbParams = NbParams(numsub);
+    if (aNbParams == 0)
+    {
+      Handle(String) anErrMess = new String("Parameter n0.%d (%s) is an empty LIST");
+      sprintf(txtmes, anErrMess->ToCString(), nump, mess);
+      ach->AddWarning(txtmes, anErrMess->ToCString());
+    }
+    return Standard_True;
   }
   //  Si optionel indefini, on passe l eponge
   numsub                  = 0;