Backport pull request #11743 from jellyfin/release-10.9.z

Fix replace logic

Original-merge: 2ddb15c7845a944d980364209c2304f03cebf025

Merged-by: joshuaboniface <joshua@boniface.me>

Backported-by: Joshua M. Boniface <joshua@boniface.me>

1 files changed, 19 insertions, 2 deletions

diff --git a/MediaBrowser.Providers/Playlists/PlaylistMetadataService.cs b/MediaBrowser.Providers/Playlists/PlaylistMetadataService.cs
index 1bd000a48..43889bfbf 100644
--- a/MediaBrowser.Providers/Playlists/PlaylistMetadataService.cs
+++ b/MediaBrowser.Providers/Playlists/PlaylistMetadataService.cs
@@ -1,6 +1,7 @@
 #pragma warning disable CS1591
 
 using System.Collections.Generic;
+using System.Linq;
 using MediaBrowser.Controller.Configuration;
 using MediaBrowser.Controller.Entities;
 using MediaBrowser.Controller.Library;
@@ -49,8 +50,24 @@ namespace MediaBrowser.Providers.Playlists
             if (mergeMetadataSettings)
             {
                 targetItem.PlaylistMediaType = sourceItem.PlaylistMediaType;
-                targetItem.LinkedChildren = sourceItem.LinkedChildren;
-                targetItem.Shares = sourceItem.Shares;
+
+                if (replaceData || targetItem.LinkedChildren.Length == 0)
+                {
+                    targetItem.LinkedChildren = sourceItem.LinkedChildren;
+                }
+                else
+                {
+                    targetItem.LinkedChildren = sourceItem.LinkedChildren.Concat(targetItem.LinkedChildren).Distinct().ToArray();
+                }
+
+                if (replaceData || targetItem.Shares.Count == 0)
+                {
+                    targetItem.Shares = sourceItem.Shares;
+                }
+                else
+                {
+                    targetItem.Shares = sourceItem.Shares.Concat(targetItem.Shares).DistinctBy(s => s.UserId).ToArray();
+                }
             }
         }
     }