From 59bf1c10af35ac7b2ac5a750a57b643efbb0969f Mon Sep 17 00:00:00 2001
From: Ghostkeeper <rubend@tutanota.com>
Date: Wed, 2 Sep 2020 03:21:11 +0200
Subject: [PATCH] Account for the fact that global_stack may be empty

You should not have any models in your scene then though. But oh well. It also fixes the typing.

Contributes to issue CURA-7118.
---
 cura/Scene/ConvexHullDecorator.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/cura/Scene/ConvexHullDecorator.py b/cura/Scene/ConvexHullDecorator.py
index 898e3546dd..bca3cdc240 100644
--- a/cura/Scene/ConvexHullDecorator.py
+++ b/cura/Scene/ConvexHullDecorator.py
@@ -381,7 +381,8 @@ class ConvexHullDecorator(SceneNodeDecorator):
         :return: New Polygon instance that is offset with everything that
         influences the collision area.
         """
-
+        if not self._global_stack:  # Should never happen.
+            return convex_hull
         scale_factor = self._global_stack.getProperty("material_shrinkage_percentage", "value") / 100.0
         result = convex_hull
         if scale_factor != 1.0: