From 71af50f67541fcac80c4e1e97b8028aad761a3c3 Mon Sep 17 00:00:00 2001
From: Dan Balasescu <smoogipoo@smgi.me>
Date: Mon, 7 Apr 2025 20:55:50 +0900
Subject: [PATCH] Validate state with lesser magic

---
 .../Multiplayer/MultiplayerMatchSubScreen.cs       | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/osu.Game/Screens/OnlinePlay/Multiplayer/MultiplayerMatchSubScreen.cs b/osu.Game/Screens/OnlinePlay/Multiplayer/MultiplayerMatchSubScreen.cs
index f1736903df..f1eeae2d61 100644
--- a/osu.Game/Screens/OnlinePlay/Multiplayer/MultiplayerMatchSubScreen.cs
+++ b/osu.Game/Screens/OnlinePlay/Multiplayer/MultiplayerMatchSubScreen.cs
@@ -518,9 +518,19 @@ namespace osu.Game.Screens.OnlinePlay.Multiplayer
                 return;
             }
 
-            if (beatmapAvailabilityTracker.Availability.Value.State != DownloadState.LocallyAvailable)
-                return;
+            // Ensure all the gameplay states are up-to-date, forgoing any misordering/scheduling shenanigans.
+            updateGameplayState();
 
+            // ... And then check that the set gameplay state is valid.
+            // When spectating, we'll receive LoadRequested() from the server even though we may not yet have the beatmap.
+            // In that case, this method will be invoked again after availability changes in onBeatmapAvailabilityChanged().
+            if (Beatmap.IsDefault)
+            {
+                Logger.Log("Aborting gameplay start - beatmap not downloaded.");
+                return;
+            }
+
+            // Start the gameplay session.
             sampleStart?.Play();
 
             int[] userIds = client.CurrentMatchPlayingUserIds.ToArray();