From 2d74609f5030b07844fab427bb4f11e7915ebdbd Mon Sep 17 00:00:00 2001
From: Dean Herbert <pe@ppy.sh>
Date: Sun, 26 Jan 2020 19:06:50 +0900
Subject: [PATCH] Fix crash due to misordered selection events

---
 osu.Game/Screens/Select/BeatmapCarousel.cs | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/osu.Game/Screens/Select/BeatmapCarousel.cs b/osu.Game/Screens/Select/BeatmapCarousel.cs
index 4433543ca1..420aa14a99 100644
--- a/osu.Game/Screens/Select/BeatmapCarousel.cs
+++ b/osu.Game/Screens/Select/BeatmapCarousel.cs
@@ -559,6 +559,14 @@ namespace osu.Game.Screens.Select
                 {
                     if (state.NewValue == CarouselItemState.Selected)
                     {
+                        if (!AllowSelection)
+                        {
+                            // CarouselBeatmap may trigger a state change from OnClick, unaware that it is not allowed to.
+                            // we revert this change here to ensure sanity.
+                            c.State.Value = state.OldValue;
+                            return;
+                        }
+
                         selectedBeatmapSet = set;
                         SelectionChanged?.Invoke(c.Beatmap);