From aa58fa58cb6f2d5a3679a60e5f8fb5f44fd7a8e0 Mon Sep 17 00:00:00 2001
From: Dan Balasescu <smoogipoo@smgi.me>
Date: Wed, 2 Apr 2025 17:59:52 +0900
Subject: [PATCH] Add deduping for active mods, add documentation

---
 .../Multiplayer/Match/MultiplayerUserModSelectOverlay.cs     | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/osu.Game/Screens/OnlinePlay/Multiplayer/Match/MultiplayerUserModSelectOverlay.cs b/osu.Game/Screens/OnlinePlay/Multiplayer/Match/MultiplayerUserModSelectOverlay.cs
index c66e1a906c..692ef0fd2f 100644
--- a/osu.Game/Screens/OnlinePlay/Multiplayer/Match/MultiplayerUserModSelectOverlay.cs
+++ b/osu.Game/Screens/OnlinePlay/Multiplayer/Match/MultiplayerUserModSelectOverlay.cs
@@ -91,7 +91,10 @@ namespace osu.Game.Screens.OnlinePlay.Multiplayer.Match
             if (!newUserMods.SequenceEqual(SelectedMods.Value))
                 SelectedMods.Value = newUserMods;
 
-            ActiveMods.Value = ComputeActiveMods();
+            // The active mods include the playlist item's required mods which change separately from the selected mods.
+            IReadOnlyList<Mod> newActiveMods = ComputeActiveMods();
+            if (!newActiveMods.SequenceEqual(ActiveMods.Value))
+                ActiveMods.Value = ComputeActiveMods();
         }
 
         protected override IReadOnlyList<Mod> ComputeActiveMods()