Perform ordering using IComparable instead

osu.Game.Tests/NonVisual/RulesetInfoOrderingTest.cs

@@ -25,7 +25,7 @@ namespace osu.Game.Tests.NonVisual
                 new RulesetInfo("custom3", "Custom Ruleset 3", string.Empty, -1),
             };
 
-            var orderedRulesets = rulesets.OrderBy(r => r.SortID);
+            var orderedRulesets = rulesets.OrderBy(r => r);
 
             // Ensure all customs are after official.
             Assert.That(orderedRulesets.Select(r => r.OnlineID), Is.EqualTo(new[] { 0, 2, -1, -1, -1, -1 }));

osu.Game/Rulesets/EFRulesetInfo.cs

@@ -42,6 +42,8 @@ namespace osu.Game.Rulesets
 
         public bool Equals(EFRulesetInfo other) => other != null && ID == other.ID && Available == other.Available && Name == other.Name && InstantiationInfo == other.InstantiationInfo;
 
+        public int CompareTo(RulesetInfo other) => ID?.CompareTo(other.ID) ?? -1;
+
         public override bool Equals(object obj) => obj is EFRulesetInfo rulesetInfo && Equals(rulesetInfo);
 
         public bool Equals(IRulesetInfo other) => other is RulesetInfo b && Equals(b);

osu.Game/Rulesets/IRulesetInfo.cs

@@ -11,7 +11,7 @@ namespace osu.Game.Rulesets
     /// <summary>
     /// A representation of a ruleset's metadata.
     /// </summary>
-    public interface IRulesetInfo : IHasOnlineID<int>, IEquatable<IRulesetInfo>
+    public interface IRulesetInfo : IHasOnlineID<int>, IEquatable<IRulesetInfo>, IComparable<RulesetInfo>
     {
         /// <summary>
         /// The user-exposed name of this ruleset.

osu.Game/Rulesets/RulesetInfo.cs

@@ -24,11 +24,6 @@ namespace osu.Game.Rulesets
 
         public string InstantiationInfo { get; set; } = string.Empty;
 
-        /// <summary>
-        /// A best effort sort ID which provides stable ordering and puts online rulesets before non-online rulesets.
-        /// </summary>
-        public int SortID => OnlineID >= 0 ? OnlineID : Math.Abs(ShortName.GetHashCode());
-
         public RulesetInfo(string shortName, string name, string instantiationInfo, int onlineID)
         {
             ShortName = shortName;
@@ -62,6 +57,20 @@ namespace osu.Game.Rulesets
 
         public bool Equals(IRulesetInfo? other) => other is RulesetInfo b && Equals(b);
 
+        public int CompareTo(RulesetInfo other)
+        {
+            // Official rulesets are always given precedence for the time being.
+            if (OnlineID >= 0)
+            {
+                if (other.OnlineID >= 0)
+                    return OnlineID.CompareTo(other.OnlineID);
+
+                return -1;
+            }
+
+            return string.Compare(ShortName, other.ShortName, StringComparison.Ordinal);
+        }
+
         public override int GetHashCode()
         {
             // Importantly, ignore the underlying realm hash code, as it will usually not match.

osu.Game/Rulesets/RulesetStore.cs

@@ -163,7 +163,7 @@ namespace osu.Game.Rulesets
                     }
                 }
 
-                availableRulesets.AddRange(detachedRulesets.OrderBy(r => r.SortID));
+                availableRulesets.AddRange(detachedRulesets.OrderBy(r => r));
             });
         }
 

osu.Game/Screens/Select/Carousel/CarouselBeatmap.cs

@@ -89,7 +89,7 @@ namespace osu.Game.Screens.Select.Carousel
             {
                 default:
                 case SortMode.Difficulty:
-                    int ruleset = BeatmapInfo.Ruleset.SortID.CompareTo(otherBeatmap.BeatmapInfo.Ruleset.SortID);
+                    int ruleset = BeatmapInfo.Ruleset.CompareTo(otherBeatmap.BeatmapInfo.Ruleset);
                     if (ruleset != 0) return ruleset;
 
                     return BeatmapInfo.StarRating.CompareTo(otherBeatmap.BeatmapInfo.StarRating);

osu.Game/Screens/Select/Carousel/CarouselBeatmapSet.cs

@@ -39,7 +39,7 @@ namespace osu.Game.Screens.Select.Carousel
 
             beatmapSet.Beatmaps
                       .Where(b => !b.Hidden)
-                      .OrderBy(b => b.Ruleset.SortID)
+                      .OrderBy(b => b.Ruleset)
                       .ThenBy(b => b.StarRating)
                       .Select(b => new CarouselBeatmap(b))
                       .ForEach(AddChild);