From 2408011c81882b71f49d5dda9d1ae98976d2058d Mon Sep 17 00:00:00 2001
From: smoogipoo <smoogipoo@smgi.me>
Date: Fri, 29 Oct 2021 16:44:39 +0900
Subject: [PATCH] Don't replace identical playlist items

---
 .../TestSceneHostOnlyQueueingMode.cs           | 18 +++++++++++++++---
 .../Online/Multiplayer/MultiplayerClient.cs    |  9 +++++++--
 2 files changed, 22 insertions(+), 5 deletions(-)

diff --git a/osu.Game.Tests/Visual/Multiplayer/QueueingModes/TestSceneHostOnlyQueueingMode.cs b/osu.Game.Tests/Visual/Multiplayer/QueueingModes/TestSceneHostOnlyQueueingMode.cs
index ada04abc5a..59baccf181 100644
--- a/osu.Game.Tests/Visual/Multiplayer/QueueingModes/TestSceneHostOnlyQueueingMode.cs
+++ b/osu.Game.Tests/Visual/Multiplayer/QueueingModes/TestSceneHostOnlyQueueingMode.cs
@@ -17,9 +17,19 @@ namespace osu.Game.Tests.Visual.Multiplayer.QueueingModes
         protected override QueueModes Mode => QueueModes.HostOnly;
 
         [Test]
-        public void TestItemStillSelectedAfterChange()
+        public void TestItemStillSelectedAfterChangeToSameBeatmap()
+        {
+            selectNewItem(() => InitialBeatmap);
+
+            AddAssert("playlist item still selected", () => Client.CurrentMatchPlayingItem.Value == Client.APIRoom?.Playlist[0]);
+        }
+
+        [Test]
+        public void TestItemStillSelectedAfterChangeToOtherBeatmap()
         {
             selectNewItem(() => OtherBeatmap);
+
+            AddAssert("playlist item still selected", () => Client.CurrentMatchPlayingItem.Value == Client.APIRoom?.Playlist[0]);
         }
 
         [Test]
@@ -57,9 +67,11 @@ namespace osu.Game.Tests.Visual.Multiplayer.QueueingModes
 
             AddUntilStep("wait for song select", () => CurrentSubScreen is Screens.Select.SongSelect select && select.IsLoaded);
 
-            AddStep("select other beatmap", () => ((Screens.Select.SongSelect)CurrentSubScreen).FinaliseSelection(beatmap()));
+            BeatmapInfo otherBeatmap = null;
+            AddStep("select other beatmap", () => ((Screens.Select.SongSelect)CurrentSubScreen).FinaliseSelection(otherBeatmap = beatmap()));
+
             AddUntilStep("wait for return to match", () => CurrentSubScreen is MultiplayerMatchSubScreen);
-            AddUntilStep("selected item is new beatmap", () => Client.CurrentMatchPlayingItem.Value?.Beatmap.Value?.OnlineID == OtherBeatmap.OnlineID);
+            AddUntilStep("selected item is new beatmap", () => Client.CurrentMatchPlayingItem.Value?.Beatmap.Value?.OnlineID == otherBeatmap.OnlineID);
         }
     }
 }
diff --git a/osu.Game/Online/Multiplayer/MultiplayerClient.cs b/osu.Game/Online/Multiplayer/MultiplayerClient.cs
index cdf6684112..d3e1a7c91a 100644
--- a/osu.Game/Online/Multiplayer/MultiplayerClient.cs
+++ b/osu.Game/Online/Multiplayer/MultiplayerClient.cs
@@ -623,11 +623,16 @@ namespace osu.Game.Online.Multiplayer
                 Debug.Assert(APIRoom != null);
 
                 int index = APIRoom.Playlist.Select((i, index) => (i, index)).Single(kvp => kvp.i.ID == item.ID).index;
+                var oldItem = APIRoom.Playlist[index];
+                if (oldItem.Equals(playlistItem))
+                    return;
+
+                // Replace the item.
                 APIRoom.Playlist.RemoveAt(index);
                 APIRoom.Playlist.Insert(index, playlistItem);
 
-                // If the current item changed, update the selected playlist item.
-                if (item.ID == Room.Settings.PlaylistItemId)
+                // If the currently-selected item was the one that got replaced, update the selected item to the new one.
+                if (CurrentMatchPlayingItem.Value == oldItem)
                     CurrentMatchPlayingItem.Value = APIRoom.Playlist[index];
             }).ConfigureAwait(false);
         }