From 7d63b03dd37c9b597df62ae20345c63829a8a4d9 Mon Sep 17 00:00:00 2001
From: Dion Moult <dion@thinkmoult.com>
Date: Tue, 4 Oct 2022 14:23:02 +1100
Subject: [PATCH] Fix bug where linking an element twice caused stacked undos
 to fail. See #2200.

---
 src/blenderbim/blenderbim/bim/ifc.py | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/blenderbim/blenderbim/bim/ifc.py b/src/blenderbim/blenderbim/bim/ifc.py
index bad89dea4c..6d0b7a35d4 100644
--- a/src/blenderbim/blenderbim/bim/ifc.py
+++ b/src/blenderbim/blenderbim/bim/ifc.py
@@ -277,6 +277,11 @@ class IfcStore:
 
     @staticmethod
     def link_element(element, obj):
+        existing_obj = IfcStore.id_map.get(element.id(), None)
+        if existing_obj == obj:
+            return
+        elif existing_obj:
+            IfcStore.unlink_element(obj=existing_obj)
         IfcStore.id_map[element.id()] = obj
         if hasattr(element, "GlobalId"):
             IfcStore.guid_map[element.GlobalId] = obj