From 85b42a16d960c4ca11dbb8288ad08cf12a0291dc Mon Sep 17 00:00:00 2001
From: Yorik van Havre <yorik@uncreated.net>
Date: Tue, 3 Apr 2018 13:30:11 -0300
Subject: [PATCH] Draft: Fixed possible bug when removing trackers

---
 src/Mod/Draft/DraftTrackers.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/Mod/Draft/DraftTrackers.py b/src/Mod/Draft/DraftTrackers.py
index bb793b2277..d0593f697f 100644
--- a/src/Mod/Draft/DraftTrackers.py
+++ b/src/Mod/Draft/DraftTrackers.py
@@ -83,7 +83,8 @@ class Tracker:
         '''remove self.switch from the scene graph.  As with _insertSwitch,
         must not be called during scene graph traversal).'''
         sg=Draft.get3DView().getSceneGraph()
-        sg.removeChild(switch)
+        if sg.findChild(switch) >= 0:
+            sg.removeChild(switch)
 
     def on(self):
         self.switch.whichChild = 0