From 274e33184b8afb9d10ef8b2d380edc8b742ee2ab Mon Sep 17 00:00:00 2001
From: smoogipoo <smoogipoo@smgi.me>
Date: Fri, 16 Apr 2021 18:22:22 +0900
Subject: [PATCH] Fix SpectatorScreen potentially missing user playing
 callbacks

---
 osu.Game/Screens/Spectate/SpectatorScreen.cs | 42 ++++++++++++++------
 1 file changed, 29 insertions(+), 13 deletions(-)

diff --git a/osu.Game/Screens/Spectate/SpectatorScreen.cs b/osu.Game/Screens/Spectate/SpectatorScreen.cs
index 6dd3144fc8..7be6c6183b 100644
--- a/osu.Game/Screens/Spectate/SpectatorScreen.cs
+++ b/osu.Game/Screens/Spectate/SpectatorScreen.cs
@@ -62,26 +62,42 @@ namespace osu.Game.Screens.Spectate
         {
             base.LoadComplete();
 
-            spectatorClient.OnUserBeganPlaying += userBeganPlaying;
-            spectatorClient.OnUserFinishedPlaying += userFinishedPlaying;
-            spectatorClient.OnNewFrames += userSentFrames;
-
-            foreach (var id in userIds)
+            populateAllUsers().ContinueWith(_ => Schedule(() =>
             {
-                userLookupCache.GetUserAsync(id).ContinueWith(u => Schedule(() =>
+                spectatorClient.BindUserBeganPlaying(userBeganPlaying, true);
+                spectatorClient.OnUserFinishedPlaying += userFinishedPlaying;
+                spectatorClient.OnNewFrames += userSentFrames;
+
+                managerUpdated = beatmaps.ItemUpdated.GetBoundCopy();
+                managerUpdated.BindValueChanged(beatmapUpdated);
+
+                lock (stateLock)
                 {
-                    if (u.Result == null)
+                    foreach (var (id, _) in userMap)
+                        spectatorClient.WatchUser(id);
+                }
+            }));
+        }
+
+        private Task populateAllUsers()
+        {
+            var userLookupTasks = new Task[userIds.Length];
+
+            for (int i = 0; i < userIds.Length; i++)
+            {
+                var userId = userIds[i];
+
+                userLookupTasks[i] = userLookupCache.GetUserAsync(userId).ContinueWith(task =>
+                {
+                    if (!task.IsCompletedSuccessfully)
                         return;
 
                     lock (stateLock)
-                        userMap[id] = u.Result;
-
-                    spectatorClient.WatchUser(id);
-                }), TaskContinuationOptions.OnlyOnRanToCompletion);
+                        userMap[userId] = task.Result;
+                });
             }
 
-            managerUpdated = beatmaps.ItemUpdated.GetBoundCopy();
-            managerUpdated.BindValueChanged(beatmapUpdated);
+            return Task.WhenAll(userLookupTasks);
         }
 
         private void beatmapUpdated(ValueChangedEvent<WeakReference<BeatmapSetInfo>> e)