From ff2eac79d14934b5d6e179d38792d196484b77bd Mon Sep 17 00:00:00 2001
From: OliBomby <olivierschipper@gmail.com>
Date: Sat, 27 Aug 2022 17:43:32 +0200
Subject: [PATCH] fix same time merge causing crash

---
 .../Editor/TestSceneObjectMerging.cs          | 29 ++++++++++++++++++-
 .../Edit/OsuSelectionHandler.cs               |  2 ++
 2 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/osu.Game.Rulesets.Osu.Tests/Editor/TestSceneObjectMerging.cs b/osu.Game.Rulesets.Osu.Tests/Editor/TestSceneObjectMerging.cs
index 4673c3d1d9..5c5384e0b7 100644
--- a/osu.Game.Rulesets.Osu.Tests/Editor/TestSceneObjectMerging.cs
+++ b/osu.Game.Rulesets.Osu.Tests/Editor/TestSceneObjectMerging.cs
@@ -190,7 +190,7 @@ public void TestIllegalMerge()
             AddStep("add two circles on the same position", () =>
             {
                 circle1 = new HitCircle();
-                circle2 = new HitCircle { Position = circle1.Position + Vector2.UnitX, StartTime = 1 };
+                circle2 = new HitCircle { Position = circle1.Position + Vector2.UnitX };
                 EditorClock.Seek(0);
                 EditorBeatmap.Add(circle1);
                 EditorBeatmap.Add(circle2);
@@ -205,6 +205,33 @@ public void TestIllegalMerge()
                                                                       && EditorBeatmap.HitObjects.Contains(circle1) && EditorBeatmap.HitObjects.Contains(circle2));
         }
 
+        [Test]
+        public void TestSameStartTimeMerge()
+        {
+            HitCircle? circle1 = null;
+            HitCircle? circle2 = null;
+
+            AddStep("add two circles at the same time", () =>
+            {
+                circle1 = new HitCircle();
+                circle2 = new HitCircle { Position = circle1.Position + 100 * Vector2.UnitX };
+                EditorClock.Seek(0);
+                EditorBeatmap.Add(circle1);
+                EditorBeatmap.Add(circle2);
+                EditorBeatmap.SelectedHitObjects.Add(circle1);
+                EditorBeatmap.SelectedHitObjects.Add(circle2);
+            });
+
+            moveMouseToHitObject(1);
+            AddAssert("merge option available", () => selectionHandler.ContextMenuItems.Any(o => o.Text.Value == "Merge selection"));
+
+            mergeSelection();
+
+            AddAssert("slider created", () => circle1 is not null && circle2 is not null && sliderCreatedFor(
+                (pos: circle1.Position, pathType: PathType.Linear),
+                (pos: circle2.Position, pathType: null)));
+        }
+
         private void mergeSelection()
         {
             AddStep("merge selection", () =>
diff --git a/osu.Game.Rulesets.Osu/Edit/OsuSelectionHandler.cs b/osu.Game.Rulesets.Osu/Edit/OsuSelectionHandler.cs
index 8b67c0dcc9..3d425afe9e 100644
--- a/osu.Game.Rulesets.Osu/Edit/OsuSelectionHandler.cs
+++ b/osu.Game.Rulesets.Osu/Edit/OsuSelectionHandler.cs
@@ -363,6 +363,7 @@ private void mergeSelection()
                 return;
 
             ChangeHandler?.BeginChange();
+            EditorBeatmap.BeginChange();
 
             // Have an initial slider object.
             var firstHitObject = mergeableObjects[0];
@@ -438,6 +439,7 @@ private void mergeSelection()
             SelectedItems.Clear();
             SelectedItems.Add(mergedHitObject);
 
+            EditorBeatmap.EndChange();
             ChangeHandler?.EndChange();
         }