From 377ba2673aa1f6869e7bca74de95df2e99717365 Mon Sep 17 00:00:00 2001
From: Dean Herbert <pe@ppy.sh>
Date: Mon, 22 Nov 2021 16:52:54 +0900
Subject: [PATCH 1/2] Use `Ruleset`'s `ShortName` for mod caching purposes

---
 osu.Game/Rulesets/Ruleset.cs | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/osu.Game/Rulesets/Ruleset.cs b/osu.Game/Rulesets/Ruleset.cs
index ade763eed8..a252bd4786 100644
--- a/osu.Game/Rulesets/Ruleset.cs
+++ b/osu.Game/Rulesets/Ruleset.cs
@@ -39,7 +39,7 @@ namespace osu.Game.Rulesets
     {
         public RulesetInfo RulesetInfo { get; internal set; }
 
-        private static readonly ConcurrentDictionary<int, IMod[]> mod_reference_cache = new ConcurrentDictionary<int, IMod[]>();
+        private static readonly ConcurrentDictionary<string, IMod[]> mod_reference_cache = new ConcurrentDictionary<string, IMod[]>();
 
         /// <summary>
         /// A queryable source containing all available mods.
@@ -49,11 +49,8 @@ namespace osu.Game.Rulesets
         {
             get
             {
-                if (!(RulesetInfo.ID is int id))
-                    return CreateAllMods();
-
-                if (!mod_reference_cache.TryGetValue(id, out var mods))
-                    mod_reference_cache[id] = mods = CreateAllMods().Cast<IMod>().ToArray();
+                if (!mod_reference_cache.TryGetValue(ShortName, out var mods))
+                    mod_reference_cache[ShortName] = mods = CreateAllMods().Cast<IMod>().ToArray();
 
                 return mods;
             }

From 6c36770eb388fe80f079b6001e7f4899bc1f20c9 Mon Sep 17 00:00:00 2001
From: Dean Herbert <pe@ppy.sh>
Date: Mon, 22 Nov 2021 21:41:09 +0900
Subject: [PATCH 2/2] Add back allowance for tests scenes using empty
 `ShortName`

---
 osu.Game/Rulesets/Ruleset.cs | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/osu.Game/Rulesets/Ruleset.cs b/osu.Game/Rulesets/Ruleset.cs
index a252bd4786..31ebcfd600 100644
--- a/osu.Game/Rulesets/Ruleset.cs
+++ b/osu.Game/Rulesets/Ruleset.cs
@@ -49,6 +49,10 @@ namespace osu.Game.Rulesets
         {
             get
             {
+                // Is the case for many test usages.
+                if (string.IsNullOrEmpty(ShortName))
+                    return CreateAllMods();
+
                 if (!mod_reference_cache.TryGetValue(ShortName, out var mods))
                     mod_reference_cache[ShortName] = mods = CreateAllMods().Cast<IMod>().ToArray();