From 8902e18da6c975cf54f20f7fb11e8f2e44acd764 Mon Sep 17 00:00:00 2001
From: Sergo <usakhelo@users.noreply.github.com>
Date: Thu, 9 Jun 2016 00:09:06 -0400
Subject: [PATCH] filter objects to exclude duplicates during copy

---
 src/Gui/MainWindow.cpp | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/Gui/MainWindow.cpp b/src/Gui/MainWindow.cpp
index 8a5a069d7465..33d651e118fc 100644
--- a/src/Gui/MainWindow.cpp
+++ b/src/Gui/MainWindow.cpp
@@ -1318,10 +1318,12 @@ void MainWindow::dragEnterEvent (QDragEnterEvent * e)
 QMimeData * MainWindow::createMimeDataFromSelection () const
 {
     std::vector<SelectionSingleton::SelObj> selobj = Selection().getCompleteSelection();
+	std::set<App::DocumentObject*> unique_objs;
     std::map< App::Document*, std::vector<App::DocumentObject*> > objs;
     for (std::vector<SelectionSingleton::SelObj>::iterator it = selobj.begin(); it != selobj.end(); ++it) {
         if (it->pObject && it->pObject->getDocument()) {
-            objs[it->pObject->getDocument()].push_back(it->pObject);
+			if (unique_objs.insert(it->pObject).second)
+	            objs[it->pObject->getDocument()].push_back(it->pObject);
         }
     }