From 303d0c56c32fc75e3fa3531ffeaaff0753f06190 Mon Sep 17 00:00:00 2001
From: Dan Balasescu <smoogipoo@smgi.me>
Date: Mon, 24 Mar 2025 17:37:11 +0900
Subject: [PATCH] Validate freestyle selection post-selection

---
 .../MultiplayerMatchFreestyleSelect.cs        |  3 ++
 .../OnlinePlay/OnlinePlayFreestyleSelect.cs   | 35 +++++++++++++++++++
 .../Playlists/PlaylistsRoomFreestyleSelect.cs |  7 ++--
 3 files changed, 40 insertions(+), 5 deletions(-)

diff --git a/osu.Game/Screens/OnlinePlay/Multiplayer/MultiplayerMatchFreestyleSelect.cs b/osu.Game/Screens/OnlinePlay/Multiplayer/MultiplayerMatchFreestyleSelect.cs
index 0c04c2712c..846f781cdc 100644
--- a/osu.Game/Screens/OnlinePlay/Multiplayer/MultiplayerMatchFreestyleSelect.cs
+++ b/osu.Game/Screens/OnlinePlay/Multiplayer/MultiplayerMatchFreestyleSelect.cs
@@ -60,6 +60,9 @@ namespace osu.Game.Screens.OnlinePlay.Multiplayer
                 return false;
             }
 
+            if (!base.OnStart())
+                return false;
+
             selectionOperation = operationTracker.BeginOperation();
 
             client.ChangeUserStyle(Beatmap.Value.BeatmapInfo.OnlineID, Ruleset.Value.OnlineID)
diff --git a/osu.Game/Screens/OnlinePlay/OnlinePlayFreestyleSelect.cs b/osu.Game/Screens/OnlinePlay/OnlinePlayFreestyleSelect.cs
index 4844d096ce..66218c0e9e 100644
--- a/osu.Game/Screens/OnlinePlay/OnlinePlayFreestyleSelect.cs
+++ b/osu.Game/Screens/OnlinePlay/OnlinePlayFreestyleSelect.cs
@@ -7,6 +7,7 @@ using Humanizer;
 using osu.Framework.Allocation;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
+using osu.Framework.Logging;
 using osu.Game.Beatmaps;
 using osu.Game.Database;
 using osu.Game.Online.Rooms;
@@ -43,6 +44,40 @@ namespace osu.Game.Screens.OnlinePlay
             LeftArea.Padding = new MarginPadding { Top = Header.HEIGHT };
         }
 
+        protected override bool OnStart()
+        {
+            FilterCriteria criteria = FilterControl.CreateCriteria();
+
+            // Beatmaps with too different of a duration are filtered away; this is just a final safety.
+            if (!criteria.Length.IsInRange(Beatmap.Value.BeatmapInfo.Length))
+            {
+                Logger.Log("The selected beatmap's duration differs too much from the host's selection.", level: LogLevel.Error);
+                return false;
+            }
+
+            // Beatmaps without a valid online ID are filtered away; this is just a final safety.
+            if (Beatmap.Value.BeatmapInfo.OnlineID < 0)
+            {
+                Logger.Log("The selected beatmap is not available online.", level: LogLevel.Error);
+                return false;
+            }
+
+            // Beatmaps from different sets are filtered away; this is just a final safety.
+            if (Beatmap.Value.BeatmapSetInfo.OnlineID != criteria.BeatmapSetId)
+            {
+                Logger.Log("The selected beatmap is from a different beatmap set.", level: LogLevel.Error);
+                return false;
+            }
+
+            if (Ruleset.Value.OnlineID < 0)
+            {
+                Logger.Log("The selected ruleset is not available online.", level: LogLevel.Error);
+                return false;
+            }
+
+            return true;
+        }
+
         protected override FilterControl CreateFilterControl() => new DifficultySelectFilterControl(item);
 
         protected override IEnumerable<(FooterButton button, OverlayContainer? overlay)> CreateSongSelectFooterButtons()
diff --git a/osu.Game/Screens/OnlinePlay/Playlists/PlaylistsRoomFreestyleSelect.cs b/osu.Game/Screens/OnlinePlay/Playlists/PlaylistsRoomFreestyleSelect.cs
index 9c85088cc9..1f0f92aea2 100644
--- a/osu.Game/Screens/OnlinePlay/Playlists/PlaylistsRoomFreestyleSelect.cs
+++ b/osu.Game/Screens/OnlinePlay/Playlists/PlaylistsRoomFreestyleSelect.cs
@@ -21,15 +21,12 @@ namespace osu.Game.Screens.OnlinePlay.Playlists
 
         protected override bool OnStart()
         {
-            // Beatmaps without a valid online ID are filtered away; this is just a final safety.
-            if (base.Beatmap.Value.BeatmapInfo.OnlineID < 0)
-                return false;
-
-            if (base.Ruleset.Value.OnlineID < 0)
+            if (!base.OnStart())
                 return false;
 
             Beatmap.Value = base.Beatmap.Value.BeatmapInfo;
             Ruleset.Value = base.Ruleset.Value;
+
             this.Exit();
             return true;
         }