Make song select ensure current beatmap is always playable in the active ruleset.

- Add a to TestCasePlaySongSelect testing this scenario

osu.Game.Tests/Visual/TestCasePlaySongSelect.cs

@@ -10,6 +10,7 @@ using osu.Framework.Allocation;
 using osu.Framework.Extensions;
 using osu.Framework.MathUtils;
 using osu.Game.Beatmaps;
+using osu.Game.Configuration;
 using osu.Game.Database;
 using osu.Game.Rulesets;
 using osu.Game.Screens.Select;
@@ -53,10 +54,14 @@ namespace osu.Game.Tests.Visual
             public WorkingBeatmap CurrentBeatmap => Beatmap.Value;
             public WorkingBeatmap CurrentBeatmapDetailsBeatmap => BeatmapDetails.Beatmap;
             public new BeatmapCarousel Carousel => base.Carousel;
+
+            public void SetRuleset(RulesetInfo ruleset) => Ruleset.Value = ruleset;
+
+            public int? RulesetID => Ruleset.Value.ID;
         }
 
         [BackgroundDependencyLoader]
-        private void load(OsuGameBase game)
+        private void load(OsuGameBase game, OsuConfigManager config)
         {
             TestSongSelect songSelect = null;
 
@@ -113,6 +118,24 @@ namespace osu.Game.Tests.Visual
             AddStep(@"Sort by Title", delegate { songSelect.FilterControl.Sort = SortMode.Title; });
             AddStep(@"Sort by Author", delegate { songSelect.FilterControl.Sort = SortMode.Author; });
             AddStep(@"Sort by Difficulty", delegate { songSelect.FilterControl.Sort = SortMode.Difficulty; });
+
+            AddWaitStep(5);
+
+            AddStep(@"Set unplayable WorkingBeatmap", () =>
+            {
+                var testMap = manager.GetAllUsableBeatmapSets().First().Beatmaps.First(b => b.RulesetID != 0);
+                songSelect.SetRuleset(rulesets.AvailableRulesets.First());
+                game.Beatmap.Value = manager.GetWorkingBeatmap(testMap);
+            });
+            AddAssert(@"WorkingBeatmap changed to playable ruleset", () => songSelect.RulesetID == 0 && game.Beatmap.Value.BeatmapInfo.RulesetID == 0);
+            AddStep(@"Disallow beatmap conversion", () =>
+            {
+                config.GetBindable<bool>(OsuSetting.ShowConvertedBeatmaps).Value = false;
+                game.Beatmap.Value = manager.GetWorkingBeatmap(manager.GetAllUsableBeatmapSets().First().Beatmaps.First());
+            });
+            loadNewSongSelect();
+            AddWaitStep(3);
+            AddAssert(@"Ruleset matches beatmap", () => songSelect.RulesetID == game.Beatmap.Value.BeatmapInfo.RulesetID);
         }
 
         private BeatmapSetInfo createTestBeatmapSet(int i)
@@ -134,7 +157,8 @@ namespace osu.Game.Tests.Visual
                     new BeatmapInfo
                     {
                         OnlineBeatmapID = 1234 + i,
-                        Ruleset = rulesets.AvailableRulesets.First(),
+                        Ruleset = rulesets.AvailableRulesets.ElementAt(0),
+                        RulesetID = 0,
                         Path = "normal.osu",
                         Version = "Normal",
                         BaseDifficulty = new BeatmapDifficulty
@@ -145,8 +169,9 @@ namespace osu.Game.Tests.Visual
                     new BeatmapInfo
                     {
                         OnlineBeatmapID = 1235 + i,
-                        Ruleset = rulesets.AvailableRulesets.First(),
+                        Ruleset = rulesets.AvailableRulesets.First(r => r.ID != 0),
-                        Path = "hard.osu",
+                        RulesetID = 1,
+                        Path = "hard.taiko",
                         Version = "Hard",
                         BaseDifficulty = new BeatmapDifficulty
                         {
@@ -156,8 +181,9 @@ namespace osu.Game.Tests.Visual
                     new BeatmapInfo
                     {
                         OnlineBeatmapID = 1236 + i,
-                        Ruleset = rulesets.AvailableRulesets.First(),
+                        Ruleset = rulesets.AvailableRulesets.ElementAt(2),
-                        Path = "insane.osu",
+                        RulesetID = 2,
+                        Path = "insane.fruits",
                         Version = "Insane",
                         BaseDifficulty = new BeatmapDifficulty
                         {

osu.Game/Screens/Select/SongSelect.cs

@@ -2,6 +2,7 @@
 // Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
 
 using System;
+using System.Linq;
 using System.Threading;
 using OpenTK;
 using OpenTK.Input;
@@ -9,12 +10,14 @@ using osu.Framework.Allocation;
 using osu.Framework.Audio;
 using osu.Framework.Audio.Sample;
 using osu.Framework.Audio.Track;
+using osu.Framework.Configuration;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
 using osu.Framework.Input;
 using osu.Framework.Screens;
 using osu.Framework.Threading;
 using osu.Game.Beatmaps;
+using osu.Game.Configuration;
 using osu.Game.Graphics;
 using osu.Game.Graphics.Containers;
 using osu.Game.Overlays;
@@ -63,6 +66,8 @@ namespace osu.Game.Screens.Select
         private SampleChannel sampleChangeDifficulty;
         private SampleChannel sampleChangeBeatmap;
 
+        private Bindable<bool> rulesetConversionAllowed;
+
         private CancellationTokenSource initialAddSetsTask;
 
         private DependencyContainer dependencies;
@@ -179,7 +184,7 @@ namespace osu.Game.Screens.Select
         }
 
         [BackgroundDependencyLoader(permitNulls: true)]
-        private void load(BeatmapManager beatmaps, AudioManager audio, DialogOverlay dialog, OsuGame osu, OsuColour colours)
+        private void load(BeatmapManager beatmaps, AudioManager audio, DialogOverlay dialog, OsuGame osu, OsuColour colours, OsuConfigManager config)
         {
             dependencies.CacheAs(this);
 
@@ -194,6 +199,8 @@ namespace osu.Game.Screens.Select
             if (this.beatmaps == null)
                 this.beatmaps = beatmaps;
 
+            rulesetConversionAllowed = config.GetBindable<bool>(OsuSetting.ShowConvertedBeatmaps);
+
             if (osu != null)
                 Ruleset.BindTo(osu.Ruleset);
 
@@ -217,7 +224,10 @@ namespace osu.Game.Screens.Select
             Beatmap.ValueChanged += b =>
             {
                 if (IsCurrentScreen)
+                {
                     Carousel.SelectBeatmap(b?.BeatmapInfo);
+                    ensurePlayableRuleset();
+                }
             };
         }
 
@@ -316,6 +326,7 @@ namespace osu.Game.Screens.Select
         {
             base.OnEntering(last);
 
+            ensurePlayableRuleset();
             Content.FadeInFromZero(250);
             FilterControl.Activate();
         }
@@ -441,6 +452,34 @@ namespace osu.Game.Screens.Select
             }
         }
 
+        private void ensurePlayableRuleset()
+        {
+            if (Beatmap.IsDefault)
+                // DummyBeatmap won't be playable anyway
+                return;
+
+            bool conversionAllowed = rulesetConversionAllowed.Value;
+            int? currentRuleset = Ruleset.Value.ID;
+            int beatmapRuleset = Beatmap.Value.BeatmapInfo.RulesetID;
+
+            if (currentRuleset == beatmapRuleset || conversionAllowed && beatmapRuleset == 0)
+                // Current beatmap is playable, nothing more to do
+                return;
+
+            // Otherwise, first check if the current beatmapset has any playable beatmaps
+            BeatmapInfo beatmap = Beatmap.Value.BeatmapSetInfo.Beatmaps?.FirstOrDefault(b => b.RulesetID == currentRuleset || conversionAllowed && b.RulesetID == 0);
+
+            // If it does then update the WorkingBeatmap
+            if (beatmap != null)
+            {
+                Beatmap.Value = beatmaps.GetWorkingBeatmap(beatmap);
+                return;
+            }
+
+            // If it doesn't, then update the current ruleset so that the current beatmap is playable
+            Ruleset.Value = Beatmap.Value.BeatmapInfo.Ruleset;
+        }
+
         private void onBeatmapSetAdded(BeatmapSetInfo s) => Carousel.UpdateBeatmapSet(s);
         private void onBeatmapSetRemoved(BeatmapSetInfo s) => Carousel.RemoveBeatmapSet(s);
         private void onBeatmapRestored(BeatmapInfo b) => Carousel.UpdateBeatmapSet(beatmaps.QueryBeatmapSet(s => s.ID == b.BeatmapSetInfoID));