From 1b07835aa5825fa3f8441ed801054acc46718129 Mon Sep 17 00:00:00 2001
From: David Osterberg <davost@gmail.com>
Date: Thu, 18 Feb 2021 09:52:24 +0100
Subject: [PATCH] PartDesign: Check closedness in AddSub refine function

---
 src/Mod/PartDesign/App/FeatureAddSub.cpp | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/Mod/PartDesign/App/FeatureAddSub.cpp b/src/Mod/PartDesign/App/FeatureAddSub.cpp
index 3faea289fd..335d8e3c4c 100644
--- a/src/Mod/PartDesign/App/FeatureAddSub.cpp
+++ b/src/Mod/PartDesign/App/FeatureAddSub.cpp
@@ -71,6 +71,9 @@ TopoDS_Shape FeatureAddSub::refineShapeIfActive(const TopoDS_Shape& oldShape) co
         try {
             Part::BRepBuilderAPI_RefineModel mkRefine(oldShape);
             TopoDS_Shape resShape = mkRefine.Shape();
+            if (!TopoShape(resShape).isClosed()) {
+                return oldShape;
+            }
             return resShape;
         }
         catch (Standard_Failure&) {