From 99dc46a89e12e68b91f9598b6b0f7ed7f0d5135c Mon Sep 17 00:00:00 2001
From: Jeremy Stretch <jstretch@digitalocean.com>
Date: Fri, 4 Jan 2019 11:46:53 -0500
Subject: [PATCH] Fixes #2742: Preserve cluster assignment when editing a
 device

---
 CHANGELOG.md         | 5 +++++
 netbox/dcim/forms.py | 8 +++++---
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3406e5497..8a56c967b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,11 @@ v2.5.3 (FUTURE)
 * [#2693](https://github.com/digitalocean/netbox/issues/2693) - Additional cable colors
 * [#2726](https://github.com/digitalocean/netbox/issues/2726) - Include cables in global search
 
+## Bug Fixes
+
+* [#2742](https://github.com/digitalocean/netbox/issues/2742) - Preserve cluster assignment when editing a device
+
+
 ---
 
 v2.5.2 (2018-12-21)
diff --git a/netbox/dcim/forms.py b/netbox/dcim/forms.py
index 61feba08c..c15952330 100644
--- a/netbox/dcim/forms.py
+++ b/netbox/dcim/forms.py
@@ -1213,11 +1213,13 @@ class DeviceForm(BootstrapMixin, TenancyForm, CustomFieldForm):
 
         # Initialize helper selectors
         instance = kwargs.get('instance')
+        if 'initial' not in kwargs:
+            kwargs['initial'] = {}
         # Using hasattr() instead of "is not None" to avoid RelatedObjectDoesNotExist on required field
         if instance and hasattr(instance, 'device_type'):
-            initial = kwargs.get('initial', {}).copy()
-            initial['manufacturer'] = instance.device_type.manufacturer
-            kwargs['initial'] = initial
+            kwargs['initial']['manufacturer'] = instance.device_type.manufacturer
+        if instance and instance.cluster is not None:
+            kwargs['initial']['cluster_group'] = instance.cluster.group
 
         super().__init__(*args, **kwargs)