Use temporary storage for file exports on iOS

osu.Game/Database/LegacyExporter.cs

@@ -9,6 +9,7 @@
 using System.Threading.Tasks;
 using osu.Framework.Platform;
 using osu.Game.Extensions;
+using osu.Game.IO;
 using osu.Game.Overlays.Notifications;
 using osu.Game.Utils;
 using Realms;
@@ -46,7 +47,7 @@ public abstract class LegacyExporter<TModel>
 
         protected LegacyExporter(Storage storage)
         {
-            exportStorage = storage.GetStorageForDirectory(@"exports");
+            exportStorage = (storage as OsuStorage)?.GetExportStorage() ?? storage.GetStorageForDirectory(@"exports");
             UserFileStorage = storage.GetStorageForDirectory(@"files");
         }
 

osu.Game/IO/OsuStorage.cs

@@ -61,6 +61,11 @@ public OsuStorage(GameHost host, Storage defaultStorage)
                 TryChangeToCustomStorage(out Error);
         }
 
+        /// <summary>
+        /// Returns the <see cref="Storage"/> used for storing exported files.
+        /// </summary>
+        public virtual Storage GetExportStorage() => GetStorageForDirectory(@"exports");
+
         /// <summary>
         /// Resets the custom storage path, changing the target storage to the default location.
         /// </summary>

osu.iOS/OsuGameIOS.cs

@@ -5,6 +5,8 @@
 using Foundation;
 using Microsoft.Maui.Devices;
 using osu.Framework.Graphics;
+using osu.Framework.iOS;
+using osu.Framework.Platform;
 using osu.Game;
 using osu.Game.Updater;
 using osu.Game.Utils;
@@ -19,6 +21,8 @@ public partial class OsuGameIOS : OsuGame
 
         protected override BatteryInfo CreateBatteryInfo() => new IOSBatteryInfo();
 
+        protected override Storage CreateStorage(GameHost host, Storage defaultStorage) => new OsuStorageIOS((IOSGameHost)host, defaultStorage);
+
         protected override Edges SafeAreaOverrideEdges =>
             // iOS shows a home indicator at the bottom, and adds a safe area to account for this.
             // Because we have the home indicator (mostly) hidden we don't really care about drawing in this region.

osu.iOS/OsuStorageIOS.cs

@@ -0,0 +1,23 @@
+// 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.IO;
+using osu.Framework.iOS;
+using osu.Framework.Platform;
+using osu.Game.IO;
+
+namespace osu.iOS
+{
+    public class OsuStorageIOS : OsuStorage
+    {
+        private readonly IOSGameHost host;
+
+        public OsuStorageIOS(IOSGameHost host, Storage defaultStorage)
+            : base(host, defaultStorage)
+        {
+            this.host = host;
+        }
+
+        public override Storage GetExportStorage() => new IOSStorage(Path.GetTempPath(), host);
+    }
+}