From 2bb2a74d3111ae2f2eea10996c7e2b923b18d7cb Mon Sep 17 00:00:00 2001
From: ouv <ouv@opencascade.com>
Date: Fri, 9 Aug 2013 12:04:38 +0000
Subject: [PATCH] Possibility to undo empty transactions.

---
 src/HYDROData/HYDROData_Document.cxx | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/HYDROData/HYDROData_Document.cxx b/src/HYDROData/HYDROData_Document.cxx
index 6062fd6d..bfc30b84 100644
--- a/src/HYDROData/HYDROData_Document.cxx
+++ b/src/HYDROData/HYDROData_Document.cxx
@@ -133,7 +133,12 @@ void HYDROData_Document::StartOperation()
 
 void HYDROData_Document::CommitOperation(const TCollection_ExtendedString& theName)
 {
-  myDoc->CommitCommand();
+  if( !myDoc->CommitCommand() ) // it means that there were no modifications done
+  {
+    myDoc->NewCommand();
+    NewID(); // workaround: do something just to modify the document
+    myDoc->CommitCommand();
+  }
   myTransactionsAfterSave++;
 
   if( theName.Length() != 0 )
-- 
2.39.2