From 26faef043ec1167beb55bcaa6420187c4554371c Mon Sep 17 00:00:00 2001
From: "Zheng, Lei" <realthunder.dev@gmail.com>
Date: Tue, 20 Jul 2021 21:33:18 +0800
Subject: [PATCH] App: fix crash on LinkBaseExtension::syncElementList()

Related realthunder/FreeCAD_Assembly3#744
---
 src/App/Link.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/App/Link.cpp b/src/App/Link.cpp
index bfe7107a80ef..bb16b31244dc 100644
--- a/src/App/Link.cpp
+++ b/src/App/Link.cpp
@@ -1580,8 +1580,8 @@ void LinkBaseExtension::syncElementList() {
             {
                 element->LinkedObject.setValue(xlink->getValue(), xlink->getSubValues());
             }
-        } else if(element->LinkedObject.getValue()!=link->getValue() ||
-                  element->LinkedObject.getSubValues().size())
+        } else if(link && (element->LinkedObject.getValue()!=link->getValue()
+                            || element->LinkedObject.getSubValues().size()))
         {
             element->setLink(-1,link->getValue());
         }