From 80047bbb07f11e49c95d9c47428b23760a74132c Mon Sep 17 00:00:00 2001
From: mpv <mpv@opencascade.com>
Date: Wed, 11 Nov 2015 15:51:45 +0300
Subject: [PATCH] Fix for the issue #1076

---
 src/Model/Model_Document.cpp | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/Model/Model_Document.cpp b/src/Model/Model_Document.cpp
index c6e15c7ef..f767f340e 100755
--- a/src/Model/Model_Document.cpp
+++ b/src/Model/Model_Document.cpp
@@ -634,6 +634,8 @@ bool Model_Document::canUndo()
 
 void Model_Document::undoInternal(const bool theWithSubs, const bool theSynchronize)
 {
+  if (myTransactions.empty())
+    return;
   int aNumTransactions = myTransactions.rbegin()->myOCAFNum;
   myRedos.push_back(*myTransactions.rbegin());
   myTransactions.pop_back();
-- 
2.39.2