From cab12ee55a6ce09ae2f01eed9fb8bf06a40e330a Mon Sep 17 00:00:00 2001
From: Dean Herbert <pe@ppy.sh>
Date: Wed, 17 May 2017 16:45:17 +0900
Subject: [PATCH 1/2] Reduce the possibility of recomputing drawables when
 underlying beatmap hasn't changed

---
 osu.Game/Screens/Select/BeatmapDetails.cs        |  2 ++
 .../Screens/Select/Leaderboards/Leaderboard.cs   |  2 ++
 osu.Game/Screens/Select/SongSelect.cs            | 16 ++++++++--------
 3 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/osu.Game/Screens/Select/BeatmapDetails.cs b/osu.Game/Screens/Select/BeatmapDetails.cs
index b750fc9bbe..abe54375cc 100644
--- a/osu.Game/Screens/Select/BeatmapDetails.cs
+++ b/osu.Game/Screens/Select/BeatmapDetails.cs
@@ -49,6 +49,8 @@ namespace osu.Game.Screens.Select
             get { return beatmap; }
             set
             {
+                if (beatmap == value) return;
+
                 beatmap = value;
 
                 pendingBeatmapSwitch?.Cancel();
diff --git a/osu.Game/Screens/Select/Leaderboards/Leaderboard.cs b/osu.Game/Screens/Select/Leaderboards/Leaderboard.cs
index a136e298b5..a7aa752d65 100644
--- a/osu.Game/Screens/Select/Leaderboards/Leaderboard.cs
+++ b/osu.Game/Screens/Select/Leaderboards/Leaderboard.cs
@@ -100,6 +100,8 @@ namespace osu.Game.Screens.Select.Leaderboards
             get { return beatmap; }
             set
             {
+                if (beatmap == value) return;
+
                 beatmap = value;
                 Scores = null;
 
diff --git a/osu.Game/Screens/Select/SongSelect.cs b/osu.Game/Screens/Select/SongSelect.cs
index 4438b656b0..4982ca096f 100644
--- a/osu.Game/Screens/Select/SongSelect.cs
+++ b/osu.Game/Screens/Select/SongSelect.cs
@@ -313,15 +313,15 @@ namespace osu.Game.Screens.Select
         {
             bool beatmapSetChange = false;
 
-            if (!beatmap.Equals(Beatmap?.BeatmapInfo))
+            if (beatmap.Equals(Beatmap?.BeatmapInfo))
+                return;
+
+            if (beatmap.BeatmapSetInfoID == selectionChangeNoBounce?.BeatmapSetInfoID)
+                sampleChangeDifficulty.Play();
+            else
             {
-                if (beatmap.BeatmapSetInfoID == selectionChangeNoBounce?.BeatmapSetInfoID)
-                    sampleChangeDifficulty.Play();
-                else
-                {
-                    sampleChangeBeatmap.Play();
-                    beatmapSetChange = true;
-                }
+                sampleChangeBeatmap.Play();
+                beatmapSetChange = true;
             }
 
             selectionChangeNoBounce = beatmap;

From 7bb38e927b5a0487994d3616f33b8525405d10e9 Mon Sep 17 00:00:00 2001
From: Dean Herbert <pe@ppy.sh>
Date: Wed, 17 May 2017 17:15:25 +0900
Subject: [PATCH 2/2] Fix song select reverting to first difficulty of current
 group on entering

---
 osu.Game/Screens/Select/BeatmapCarousel.cs | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/osu.Game/Screens/Select/BeatmapCarousel.cs b/osu.Game/Screens/Select/BeatmapCarousel.cs
index fbdaa948cc..4df24c1314 100644
--- a/osu.Game/Screens/Select/BeatmapCarousel.cs
+++ b/osu.Game/Screens/Select/BeatmapCarousel.cs
@@ -107,6 +107,8 @@ namespace osu.Game.Screens.Select
                 return;
             }
 
+            if (beatmap == SelectedBeatmap) return;
+
             foreach (BeatmapGroup group in groups)
             {
                 var panel = group.BeatmapPanels.FirstOrDefault(p => p.Beatmap.Equals(beatmap));
@@ -204,7 +206,7 @@ namespace osu.Game.Screens.Select
                 if (selectedGroup == null || selectedGroup.State == BeatmapGroupState.Hidden)
                     SelectNext();
                 else
-                    selectGroup(selectedGroup);
+                    selectGroup(selectedGroup, selectedPanel);
             };
 
             filterTask?.Cancel();
@@ -339,6 +341,8 @@ namespace osu.Game.Screens.Select
                     selectedGroup.State = BeatmapGroupState.Collapsed;
 
                 group.State = BeatmapGroupState.Expanded;
+                group.SelectedPanel = panel;
+
                 panel.State = PanelSelectedState.Selected;
 
                 if (selectedPanel == panel) return;