From f27617e63e4cd0ea00dd307577abe465d9a709fa Mon Sep 17 00:00:00 2001
From: wmayer <wmayer@users.sourceforge.net>
Date: Fri, 8 Sep 2017 14:52:12 +0200
Subject: [PATCH] make sure to avoid duplicate child elements in view provider
 of ruled surface

---
 src/Mod/Part/Gui/ViewProviderRuledSurface.cpp | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/src/Mod/Part/Gui/ViewProviderRuledSurface.cpp b/src/Mod/Part/Gui/ViewProviderRuledSurface.cpp
index 504a8f8b50..a92941c578 100644
--- a/src/Mod/Part/Gui/ViewProviderRuledSurface.cpp
+++ b/src/Mod/Part/Gui/ViewProviderRuledSurface.cpp
@@ -55,10 +55,14 @@ ViewProviderRuledSurface::~ViewProviderRuledSurface()
 
 std::vector<App::DocumentObject*> ViewProviderRuledSurface::claimChildren() const
 {
-    std::vector<App::DocumentObject*> temp;
-    temp.push_back(static_cast<Part::RuledSurface*>(getObject())->Curve1.getValue());
-    temp.push_back(static_cast<Part::RuledSurface*>(getObject())->Curve2.getValue());
-    return temp;
+    // in a set each element is unique
+    std::set<App::DocumentObject*> temp;
+    temp.insert(static_cast<Part::RuledSurface*>(getObject())->Curve1.getValue());
+    temp.insert(static_cast<Part::RuledSurface*>(getObject())->Curve2.getValue());
+
+    std::vector<App::DocumentObject*> array;
+    array.insert(array.begin(), temp.begin(), temp.end());
+    return array;
 }
 
 void ViewProviderRuledSurface::updateData(const App::Property* prop)