From eb1d5e13d0571e3f709ad8153021513d24b05b96 Mon Sep 17 00:00:00 2001
From: Jaime van Kessel <nallath@gmail.com>
Date: Wed, 21 Sep 2016 11:25:57 +0200
Subject: [PATCH] Only disconnect old stack if we found a new one

CURA-2361
---
 cura/Settings/SettingInheritanceManager.py | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/cura/Settings/SettingInheritanceManager.py b/cura/Settings/SettingInheritanceManager.py
index 5168fbe9c1..93a7b1370d 100644
--- a/cura/Settings/SettingInheritanceManager.py
+++ b/cura/Settings/SettingInheritanceManager.py
@@ -49,15 +49,14 @@ class SettingInheritanceManager(QObject):
         self._update()
 
     def _onActiveExtruderChanged(self):
-        if self._active_container_stack:
-            self._active_container_stack.propertyChanged.disconnect(self._onPropertyChanged)
-
         new_active_stack = cura.Settings.ExtruderManager.getInstance().getActiveExtruderStack()
         if not new_active_stack:
             new_active_stack = self._global_container_stack
 
-        if new_active_stack != self._active_container_stack:
-            # Check if changed
+        if new_active_stack != self._active_container_stack:  # Check if changed
+            if self._active_container_stack:  # Disconnect signal from old container (if any)
+                self._active_container_stack.propertyChanged.disconnect(self._onPropertyChanged)
+
             self._active_container_stack = new_active_stack
             self._active_container_stack.propertyChanged.connect(self._onPropertyChanged)
             self._update()  # Ensure that the settings_with_inheritance_warning list is populated.