From eb4acba08118b74a09d7bb23fcdc86d312f75e56 Mon Sep 17 00:00:00 2001
From: Bjarne Fyrstenborg <bjarne_fyrstenborg@hotmail.com>
Date: Wed, 12 Jan 2022 12:35:48 +0100
Subject: [PATCH] Set default tree group for core trees (#11801)

Co-authored-by: Elitsa Marinovska <elm@umbraco.dk>
---
 src/Umbraco.Core/Extensions/TypeExtensions.cs          | 10 ++++++++--
 .../Trees/TreeCollectionBuilder.cs                     |  6 ++++++
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/src/Umbraco.Core/Extensions/TypeExtensions.cs b/src/Umbraco.Core/Extensions/TypeExtensions.cs
index 67a6dd1dce..c5bc99cae8 100644
--- a/src/Umbraco.Core/Extensions/TypeExtensions.cs
+++ b/src/Umbraco.Core/Extensions/TypeExtensions.cs
@@ -430,10 +430,16 @@ namespace Umbraco.Extensions
             where T : Attribute
         {
             if (type == null) return Enumerable.Empty<T>();
-            return type.GetCustomAttributes(typeof (T), inherited).OfType<T>();
+            return type.GetCustomAttributes(typeof(T), inherited).OfType<T>();
         }
 
-          /// <summary>
+        public static bool HasCustomAttribute<T>(this Type type, bool inherit)
+            where T : Attribute
+        {
+            return type.GetCustomAttribute<T>(inherit) != null;
+        }
+
+        /// <summary>
         /// Tries to return a value based on a property name for an object but ignores case sensitivity
         /// </summary>
         /// <param name="type"></param>
diff --git a/src/Umbraco.Web.BackOffice/Trees/TreeCollectionBuilder.cs b/src/Umbraco.Web.BackOffice/Trees/TreeCollectionBuilder.cs
index d8d8afe13a..08f6d7b400 100644
--- a/src/Umbraco.Web.BackOffice/Trees/TreeCollectionBuilder.cs
+++ b/src/Umbraco.Web.BackOffice/Trees/TreeCollectionBuilder.cs
@@ -48,6 +48,12 @@ namespace Umbraco.Cms.Web.BackOffice.Trees
 
             var attribute = controllerType.GetCustomAttribute<TreeAttribute>(false);
             if (attribute == null) return;
+
+            bool isCoreTree = controllerType.HasCustomAttribute<CoreTreeAttribute>(false);
+
+            // Use section as tree group if core tree, so it isn't grouped by empty key and thus end up in "Third Party" tree group if adding custom tree nodes in other groups, e.g. "Settings" tree group.
+            attribute.TreeGroup = attribute.TreeGroup ?? (isCoreTree ? attribute.SectionAlias : attribute.TreeGroup);
+
             var tree = new Tree(attribute.SortOrder, attribute.SectionAlias, attribute.TreeGroup, attribute.TreeAlias, attribute.TreeTitle, attribute.TreeUse, controllerType, attribute.IsSingleNodeTree);
             _trees.Add(tree);
         }