patch on crash in old study

diff --git a/src/HYDROData/HYDROData_Entity.cxx b/src/HYDROData/HYDROData_Entity.cxx
index 99667f318fa8f178fdd5c154f09c1b7e236fd25c..f0b9e5fb034a06e9b26123375f8f69eab2fe0fc2 100644 (file)
--- a/src/HYDROData/HYDROData_Entity.cxx
+++ b/src/HYDROData/HYDROData_Entity.cxx
@@ -165,6 +165,8 @@ void HYDROData_Entity::Changed( Geometry theChangedGeometry )
   for ( ; anIter.More(); anIter.Next() )
   {
     Handle(HYDROData_Entity) anObject = anIter.Current();
+    if( anObject.IsNull() )
+      continue;
     HYDROData_SequenceOfObjects aRefSeq = anObject->GetAllReferenceObjects();
     for ( int i = 1, n = aRefSeq.Length(); i <= n; ++i )
     {