Merge branch 'master' into fix-leaderboard-user-handling

osu.Game.Tests/Visual/Multiplayer/TestSceneMultiplayerParticipantsList.cs

@@ -43,6 +43,16 @@ namespace osu.Game.Tests.Visual.Multiplayer
             AddAssert("two unique panels", () => this.ChildrenOfType<ParticipantPanel>().Select(p => p.User).Distinct().Count() == 2);
         }
 
+        [Test]
+        public void TestAddNullUser()
+        {
+            AddAssert("one unique panel", () => this.ChildrenOfType<ParticipantPanel>().Select(p => p.User).Distinct().Count() == 1);
+
+            AddStep("add non-resolvable user", () => Client.AddNullUser(-3));
+
+            AddUntilStep("two unique panels", () => this.ChildrenOfType<ParticipantPanel>().Select(p => p.User).Distinct().Count() == 2);
+        }
+
         [Test]
         public void TestRemoveUser()
         {

osu.Game/Database/UserLookupCache.cs

@@ -80,6 +80,7 @@ namespace osu.Game.Database
             var request = new GetUsersRequest(userTasks.Keys.ToArray());
 
             // rather than queueing, we maintain our own single-threaded request stream.
+            // todo: we probably want retry logic here.
             api.Perform(request);
 
             // Create a new request task if there's still more users to query.
@@ -90,14 +91,19 @@ namespace osu.Game.Database
                     createNewTask();
             }
 
-            foreach (var user in request.Result.Users)
+            List<User> foundUsers = request.Result?.Users;
-            {
-                if (userTasks.TryGetValue(user.Id, out var tasks))
-                {
-                    foreach (var task in tasks)
-                        task.SetResult(user);
 
-                    userTasks.Remove(user.Id);
+            if (foundUsers != null)
+            {
+                foreach (var user in foundUsers)
+                {
+                    if (userTasks.TryGetValue(user.Id, out var tasks))
+                    {
+                        foreach (var task in tasks)
+                            task.SetResult(user);
+
+                        userTasks.Remove(user.Id);
+                    }
                 }
             }
 

osu.Game/Screens/OnlinePlay/Multiplayer/Participants/ParticipantPanel.cs

@@ -1,7 +1,6 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
-using System.Diagnostics;
 using osu.Framework.Allocation;
 using osu.Framework.Extensions.Color4Extensions;
 using osu.Framework.Graphics;
@@ -45,7 +44,7 @@ namespace osu.Game.Screens.OnlinePlay.Multiplayer.Participants
         [BackgroundDependencyLoader]
         private void load()
         {
-            Debug.Assert(User.User != null);
+            var user = User.User;
 
             var backgroundColour = Color4Extensions.FromHex("#33413C");
 
@@ -82,7 +81,7 @@ namespace osu.Game.Screens.OnlinePlay.Multiplayer.Participants
                                 Origin = Anchor.CentreRight,
                                 RelativeSizeAxes = Axes.Both,
                                 Width = 0.75f,
-                                User = User.User,
+                                User = user,
                                 Colour = ColourInfo.GradientHorizontal(Color4.White.Opacity(0), Color4.White.Opacity(0.25f))
                             },
                             new FillFlowContainer
@@ -98,28 +97,28 @@ namespace osu.Game.Screens.OnlinePlay.Multiplayer.Participants
                                         Origin = Anchor.CentreLeft,
                                         RelativeSizeAxes = Axes.Both,
                                         FillMode = FillMode.Fit,
-                                        User = User.User
+                                        User = user
                                     },
                                     new UpdateableFlag
                                     {
                                         Anchor = Anchor.CentreLeft,
                                         Origin = Anchor.CentreLeft,
                                         Size = new Vector2(30, 20),
-                                        Country = User.User.Country
+                                        Country = user?.Country
                                     },
                                     new OsuSpriteText
                                     {
                                         Anchor = Anchor.CentreLeft,
                                         Origin = Anchor.CentreLeft,
                                         Font = OsuFont.GetFont(weight: FontWeight.Bold, size: 18),
-                                        Text = User.User.Username
+                                        Text = user?.Username
                                     },
                                     new OsuSpriteText
                                     {
                                         Anchor = Anchor.CentreLeft,
                                         Origin = Anchor.CentreLeft,
                                         Font = OsuFont.GetFont(size: 14),
-                                        Text = User.User.CurrentModeRank != null ? $"#{User.User.CurrentModeRank}" : string.Empty
+                                        Text = user?.CurrentModeRank != null ? $"#{user.CurrentModeRank}" : string.Empty
                                     }
                                 }
                             },

osu.Game/Tests/Visual/Multiplayer/TestMultiplayerClient.cs

@@ -28,6 +28,8 @@ namespace osu.Game.Tests.Visual.Multiplayer
 
         public void AddUser(User user) => ((IMultiplayerClient)this).UserJoined(new MultiplayerRoomUser(user.Id) { User = user });
 
+        public void AddNullUser(int userId) => ((IMultiplayerClient)this).UserJoined(new MultiplayerRoomUser(userId));
+
         public void RemoveUser(User user)
         {
             Debug.Assert(Room != null);