Add test coverage ensuring ruleset ID is correct after bracket read

Historically, tournament client may have written incorrect `OnlineID`
values. We wanted to use `ShortName` to re-fetch the ruleset. This test
ensures this flow is working correctly.

osu.Game.Tournament.Tests/NonVisual/DataLoadTest.cs

@@ -1,9 +1,13 @@
 // 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;
 using System.IO;
+using System.Threading.Tasks;
 using NUnit.Framework;
 using osu.Framework.Allocation;
+using osu.Framework.Bindables;
+using osu.Framework.Extensions;
 using osu.Framework.Platform;
 using osu.Game.Rulesets;
 using osu.Game.Tests;
@@ -12,6 +16,45 @@ namespace osu.Game.Tournament.Tests.NonVisual
 {
     public class DataLoadTest : TournamentHostTest
     {
+        [Test]
+        public void TestRulesetGetsValidOnlineID()
+        {
+            using (HeadlessGameHost host = new CleanRunHeadlessGameHost())
+            {
+                try
+                {
+                    var osu = new TestTournament(runOnLoadComplete: () =>
+                    {
+                        // ReSharper disable once AccessToDisposedClosure
+                        var storage = host.Storage.GetStorageForDirectory(Path.Combine("tournaments", "default"));
+
+                        using (var stream = storage.GetStream("bracket.json", FileAccess.Write, FileMode.Create))
+                        using (var writer = new StreamWriter(stream))
+                        {
+                            writer.Write(@"{
+                        ""Ruleset"": {
+                            ""ShortName"": ""taiko"",
+                            ""OnlineID"": -1,
+                            ""Name"": ""osu!taiko"",
+                            ""InstantiationInfo"": ""osu.Game.Rulesets.OsuTaiko.TaikoRuleset, osu.Game.Rulesets.Taiko"",
+                            ""Available"": true
+                        } }");
+                        }
+                    });
+
+                    LoadTournament(host, osu);
+
+                    osu.BracketLoadTask.WaitSafely();
+
+                    Assert.That(osu.Dependencies.Get<IBindable<RulesetInfo>>().Value.OnlineID, Is.EqualTo(1));
+                }
+                finally
+                {
+                    host.Exit();
+                }
+            }
+        }
+
         [Test]
         public void TestUnavailableRuleset()
         {
@@ -19,7 +62,7 @@ namespace osu.Game.Tournament.Tests.NonVisual
             {
                 try
                 {
-                    var osu = new TestTournament();
+                    var osu = new TestTournament(true);
 
                     LoadTournament(host, osu);
                     var storage = osu.Dependencies.Get<Storage>();
@@ -35,9 +78,22 @@ namespace osu.Game.Tournament.Tests.NonVisual
 
         public class TestTournament : TournamentGameBase
         {
+            private readonly bool resetRuleset;
+            private readonly Action runOnLoadComplete;
+
+            public new Task BracketLoadTask => base.BracketLoadTask;
+
+            public TestTournament(bool resetRuleset = false, Action runOnLoadComplete = null)
+            {
+                this.resetRuleset = resetRuleset;
+                this.runOnLoadComplete = runOnLoadComplete;
+            }
+
             protected override void LoadComplete()
             {
+                runOnLoadComplete?.Invoke();
                 base.LoadComplete();
+                if (resetRuleset)
                     Ruleset.Value = new RulesetInfo(); // not available
             }
         }

osu.Game.Tournament/TournamentGameBase.cs

@@ -64,8 +64,6 @@ namespace osu.Game.Tournament
             Textures.AddStore(new TextureLoaderStore(new StorageBackedResourceStore(storage)));
 
             dependencies.CacheAs(new StableInfo(storage));
-
-            Task.Run(readBracket);
         }
 
         private void readBracket()
@@ -290,6 +288,8 @@ namespace osu.Game.Tournament
             MenuCursorContainer.Cursor.Alpha = 0;
 
             base.LoadComplete();
+
+            Task.Run(readBracket);
         }
 
         protected virtual void SaveChanges()