1 files changed, 58 insertions, 25 deletions

diff --git a/MediaBrowser.Controller/Entities/CollectionFolder.cs b/MediaBrowser.Controller/Entities/CollectionFolder.cs
index 41e277b7c..681f16f07 100644
--- a/MediaBrowser.Controller/Entities/CollectionFolder.cs
+++ b/MediaBrowser.Controller/Entities/CollectionFolder.cs
@@ -5,14 +5,14 @@ using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
-using System.Runtime.Serialization;
 using System.Threading;
 using System.Threading.Tasks;
-using CommonIO;
+using MediaBrowser.Common.IO;
 using MediaBrowser.Controller.Configuration;
 using MediaBrowser.Model.Configuration;
+using MediaBrowser.Model.Extensions;
+using MediaBrowser.Model.IO;
 using MediaBrowser.Model.Serialization;
-using MoreLinq;
 
 namespace MediaBrowser.Controller.Entities
 {
@@ -27,6 +27,7 @@ namespace MediaBrowser.Controller.Entities
         public CollectionFolder()
         {
             PhysicalLocationsList = new List<string>();
+            PhysicalFolderIds = new List<Guid>();
         }
 
         [IgnoreDataMember]
@@ -77,7 +78,7 @@ namespace MediaBrowser.Controller.Entities
             {
                 return new LibraryOptions();
             }
-            catch (DirectoryNotFoundException)
+            catch (IOException)
             {
                 return new LibraryOptions();
             }
@@ -153,6 +154,7 @@ namespace MediaBrowser.Controller.Entities
         }
 
         public List<string> PhysicalLocationsList { get; set; }
+        public List<Guid> PhysicalFolderIds { get; set; }
 
         protected override IEnumerable<FileSystemMetadata> GetFileSystemChildren(IDirectoryService directoryService)
         {
@@ -176,6 +178,18 @@ namespace MediaBrowser.Controller.Entities
                 }
             }
 
+            if (!changed)
+            {
+                var folderIds = PhysicalFolderIds.ToList();
+
+                var newFolderIds = GetPhysicalFolders(false).Select(i => i.Id).ToList();
+
+                if (!folderIds.SequenceEqual(newFolderIds))
+                {
+                    changed = true;
+                }
+            }
+
             return changed;
         }
 
@@ -186,6 +200,39 @@ namespace MediaBrowser.Controller.Entities
             return changed;
         }
 
+        protected override bool RefreshLinkedChildren(IEnumerable<FileSystemMetadata> fileSystemChildren)
+        {
+            return RefreshLinkedChildrenInternal(true);
+        }
+
+        private bool RefreshLinkedChildrenInternal(bool setFolders)
+        {
+            var physicalFolders = GetPhysicalFolders(false)
+                .ToList();
+
+            var linkedChildren = physicalFolders
+                .SelectMany(c => c.LinkedChildren)
+                .ToList();
+
+            var changed = !linkedChildren.SequenceEqual(LinkedChildren, new LinkedChildComparer());
+
+            LinkedChildren = linkedChildren;
+
+            var folderIds = PhysicalFolderIds.ToList();
+            var newFolderIds = physicalFolders.Select(i => i.Id).ToList();
+
+            if (!folderIds.SequenceEqual(newFolderIds))
+            {
+                changed = true;
+                if (setFolders)
+                {
+                    PhysicalFolderIds = newFolderIds.ToList();
+                }
+            }
+
+            return changed;
+        }
+
         internal override bool IsValidFromResolver(BaseItem newItem)
         {
             var newCollectionFolder = newItem as CollectionFolder;
@@ -263,25 +310,6 @@ namespace MediaBrowser.Controller.Entities
         /// <summary>
         /// Our children are actually just references to the ones in the physical root...
         /// </summary>
-        /// <value>The linked children.</value>
-        public override List<LinkedChild> LinkedChildren
-        {
-            get { return GetLinkedChildrenInternal(); }
-            set
-            {
-                base.LinkedChildren = value;
-            }
-        }
-        private List<LinkedChild> GetLinkedChildrenInternal()
-        {
-            return GetPhysicalParents()
-                .SelectMany(c => c.LinkedChildren)
-                .ToList();
-        }
-
-        /// <summary>
-        /// Our children are actually just references to the ones in the physical root...
-        /// </summary>
         /// <value>The actual children.</value>
         [IgnoreDataMember]
         protected override IEnumerable<BaseItem> ActualChildren
@@ -291,11 +319,16 @@ namespace MediaBrowser.Controller.Entities
 
         private IEnumerable<BaseItem> GetActualChildren()
         {
-            return GetPhysicalParents().SelectMany(c => c.Children);
+            return GetPhysicalFolders(true).SelectMany(c => c.Children);
         }
 
-        public IEnumerable<Folder> GetPhysicalParents()
+        private IEnumerable<Folder> GetPhysicalFolders(bool enableCache)
         {
+            if (enableCache)
+            {
+                return PhysicalFolderIds.Select(i => LibraryManager.GetItemById(i)).OfType<Folder>();
+            }
+
             var rootChildren = LibraryManager.RootFolder.Children
                 .OfType<Folder>()
                 .ToList();