Fix daily challenge not showing a replay button in results screen

osu.Game.Tests/Visual/Gameplay/TestSceneReplayDownloadButton.cs

@@ -117,6 +117,9 @@ public void TestButtonWithReplayStartsDownload()
 
             AddAssert("state entered downloading", () => downloadStarted);
             AddUntilStep("state left downloading", () => downloadFinished);
+
+            AddStep("change score to null", () => downloadButton.Score.Value = null);
+            AddUntilStep("state changed to unknown", () => downloadButton.State.Value, () => Is.EqualTo(DownloadState.Unknown));
         }
 
         [Test]

osu.Game/Screens/Ranking/ReplayDownloadButton.cs

@@ -18,7 +18,7 @@ namespace osu.Game.Screens.Ranking
 {
     public partial class ReplayDownloadButton : CompositeDrawable, IKeyBindingHandler<GlobalAction>
     {
-        public readonly Bindable<ScoreInfo> Score = new Bindable<ScoreInfo>();
+        public readonly Bindable<ScoreInfo?> Score = new Bindable<ScoreInfo?>();
 
         protected readonly Bindable<DownloadState> State = new Bindable<DownloadState>();
 
@@ -44,7 +44,7 @@ private ReplayAvailability replayAvailability
             }
         }
 
-        public ReplayDownloadButton(ScoreInfo score)
+        public ReplayDownloadButton(ScoreInfo? score)
         {
             Score.Value = score;
             Size = new Vector2(50, 30);
@@ -67,11 +67,11 @@ private void load(OsuGame? game, ScoreModelDownloader scoreDownloader)
                 switch (State.Value)
                 {
                     case DownloadState.LocallyAvailable:
-                        game?.PresentScore(Score.Value, ScorePresentType.Gameplay);
+                        game?.PresentScore(Score.Value!, ScorePresentType.Gameplay);
                         break;
 
                     case DownloadState.NotDownloaded:
-                        scoreDownloader.Download(Score.Value);
+                        scoreDownloader.Download(Score.Value!);
                         break;
 
                     case DownloadState.Importing:
@@ -88,6 +88,8 @@ private void load(OsuGame? game, ScoreModelDownloader scoreDownloader)
                 State.ValueChanged -= exportWhenReady;
 
                 downloadTracker?.RemoveAndDisposeImmediately();
+                downloadTracker = null;
+                State.SetDefault();
 
                 if (score.NewValue != null)
                 {
@@ -147,7 +149,7 @@ private void exportWhenReady(ValueChangedEvent<DownloadState> state)
         {
             if (state.NewValue != DownloadState.LocallyAvailable) return;
 
-            scoreManager.Export(Score.Value);
+            scoreManager.Export(Score.Value!);
 
             State.ValueChanged -= exportWhenReady;
         }

osu.Game/Screens/Ranking/ResultsScreen.cs

@@ -179,11 +179,11 @@ private void load(AudioManager audio)
                 Scheduler.AddDelayed(() => OverlayActivationMode.Value = OverlayActivation.All, shouldFlair ? AccuracyCircle.TOTAL_DURATION + 1000 : 0);
             }
 
-            if (SelectedScore.Value != null && AllowWatchingReplay)
+            if (AllowWatchingReplay)
             {
                 buttons.Add(new ReplayDownloadButton(SelectedScore.Value)
                 {
-                    Score = { BindTarget = SelectedScore! },
+                    Score = { BindTarget = SelectedScore },
                     Width = 300
                 });
             }