From 35cee77a983c8448cdae0e26e530699820e2f022 Mon Sep 17 00:00:00 2001
From: Shadowghost <Shadowghost@users.noreply.github.com>
Date: Mon, 5 Oct 2026 19:19:08 -0400
Subject: Backport pull request #18280 from jellyfin/release-12.z

Only propagate a changed rating to children that follow it

Original-merge: 1d5590d02ac04d857e73a4e4406b0801589d3368

Merged-by: crobibero <cody@robibe.ro>

Backported-by: Cody Robibero <cody@robibe.ro>
---
 Jellyfin.Api/Controllers/ItemUpdateController.cs | 37 +++++++++++++++++++-----
 1 file changed, 29 insertions(+), 8 deletions(-)

(limited to 'Jellyfin.Api/Controllers/ItemUpdateController.cs')

diff --git a/Jellyfin.Api/Controllers/ItemUpdateController.cs b/Jellyfin.Api/Controllers/ItemUpdateController.cs
index 4859cb89c0..288efebc4f 100644
--- a/Jellyfin.Api/Controllers/ItemUpdateController.cs
+++ b/Jellyfin.Api/Controllers/ItemUpdateController.cs
@@ -292,6 +292,8 @@ public class ItemUpdateController : BaseJellyfinApiController
         item.PremiereDate = request.PremiereDate.HasValue ? NormalizeDateTime(request.PremiereDate.Value) : null;
         item.ProductionYear = request.ProductionYear;
 
+        var previousOfficialRating = item.OfficialRating;
+        var previousCustomRating = item.CustomRating;
         request.OfficialRating = string.IsNullOrWhiteSpace(request.OfficialRating) ? null : request.OfficialRating;
         item.OfficialRating = request.OfficialRating;
         item.CustomRating = request.CustomRating;
@@ -318,12 +320,14 @@ public class ItemUpdateController : BaseJellyfinApiController
             {
                 season.SeriesName = rseries.Name;
 
+                var previousSeasonOfficialRating = season.OfficialRating;
+                var previousSeasonCustomRating = season.CustomRating;
                 if (!season.LockedFields.Contains(MetadataField.OfficialRating))
                 {
-                    season.OfficialRating = request.OfficialRating;
+                    season.OfficialRating = GetPropagatedRating(season.OfficialRating, previousOfficialRating, request.OfficialRating);
                 }
 
-                season.CustomRating = request.CustomRating;
+                season.CustomRating = GetPropagatedRating(season.CustomRating, previousCustomRating, request.CustomRating);
 
                 if (!season.LockedFields.Contains(MetadataField.Tags))
                 {
@@ -339,10 +343,10 @@ public class ItemUpdateController : BaseJellyfinApiController
 
                     if (!ep.LockedFields.Contains(MetadataField.OfficialRating))
                     {
-                        ep.OfficialRating = request.OfficialRating;
+                        ep.OfficialRating = GetPropagatedRating(ep.OfficialRating, previousSeasonOfficialRating, season.OfficialRating);
                     }
 
-                    ep.CustomRating = request.CustomRating;
+                    ep.CustomRating = GetPropagatedRating(ep.CustomRating, previousSeasonCustomRating, season.CustomRating);
 
                     if (!ep.LockedFields.Contains(MetadataField.Tags))
                     {
@@ -362,10 +366,10 @@ public class ItemUpdateController : BaseJellyfinApiController
 
                 if (!ep.LockedFields.Contains(MetadataField.OfficialRating))
                 {
-                    ep.OfficialRating = request.OfficialRating;
+                    ep.OfficialRating = GetPropagatedRating(ep.OfficialRating, previousOfficialRating, request.OfficialRating);
                 }
 
-                ep.CustomRating = request.CustomRating;
+                ep.CustomRating = GetPropagatedRating(ep.CustomRating, previousCustomRating, request.CustomRating);
 
                 if (!ep.LockedFields.Contains(MetadataField.Tags))
                 {
@@ -382,10 +386,10 @@ public class ItemUpdateController : BaseJellyfinApiController
             {
                 if (!track.LockedFields.Contains(MetadataField.OfficialRating))
                 {
-                    track.OfficialRating = request.OfficialRating;
+                    track.OfficialRating = GetPropagatedRating(track.OfficialRating, previousOfficialRating, request.OfficialRating);
                 }
 
-                track.CustomRating = request.CustomRating;
+                track.CustomRating = GetPropagatedRating(track.CustomRating, previousCustomRating, request.CustomRating);
 
                 if (!track.LockedFields.Contains(MetadataField.Tags))
                 {
@@ -477,6 +481,23 @@ public class ItemUpdateController : BaseJellyfinApiController
         }
     }
 
+    /// <summary>
+    /// Gets the rating a child should carry after its parent's rating changed from <paramref name="previousRating"/>
+    /// to <paramref name="newRating"/>: a child with no rating, or the parent's previous one, follows the parent.
+    /// A child with a rating of its own, or any child when the parent's rating did not change, keeps its rating.
+    /// </summary>
+    private static string? GetPropagatedRating(string? childRating, string? previousRating, string? newRating)
+    {
+        if (string.Equals(previousRating ?? string.Empty, newRating ?? string.Empty, StringComparison.OrdinalIgnoreCase))
+        {
+            return childRating;
+        }
+
+        return string.IsNullOrEmpty(childRating) || string.Equals(childRating, previousRating, StringComparison.OrdinalIgnoreCase)
+            ? newRating
+            : childRating;
+    }
+
     private SeriesStatus? GetSeriesStatus(BaseItemDto item)
     {
         if (string.IsNullOrEmpty(item.Status))
-- 
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