From d56accaef1ab193f33d214a16e53a56a8e22be49 Mon Sep 17 00:00:00 2001
From: Dean Herbert <pe@ppy.sh>
Date: Wed, 5 Feb 2020 15:32:51 +0900
Subject: [PATCH] Disallow negative / zero repeat counts (and fix off-by-one)

---
 .../Components/Timeline/TimelineHitObjectBlueprint.cs    | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/osu.Game/Screens/Edit/Compose/Components/Timeline/TimelineHitObjectBlueprint.cs b/osu.Game/Screens/Edit/Compose/Components/Timeline/TimelineHitObjectBlueprint.cs
index 2ac35534f4..b2da1577d0 100644
--- a/osu.Game/Screens/Edit/Compose/Components/Timeline/TimelineHitObjectBlueprint.cs
+++ b/osu.Game/Screens/Edit/Compose/Components/Timeline/TimelineHitObjectBlueprint.cs
@@ -119,7 +119,14 @@ namespace osu.Game.Screens.Edit.Compose.Components.Timeline
                 switch (hitObject)
                 {
                     case IHasRepeats repeatHitObject:
-                        repeatHitObject.RepeatCount = (int)((time - hitObject.StartTime) / (repeatHitObject.Duration / repeatHitObject.RepeatCount));
+                        // find the number of repeats which can fit in the requested time.
+                        var lengthOfOneRepeat = repeatHitObject.Duration / (repeatHitObject.RepeatCount + 1);
+                        var proposedCount = (int)((time - hitObject.StartTime) / lengthOfOneRepeat) - 1;
+
+                        if (proposedCount == repeatHitObject.RepeatCount || proposedCount < 0)
+                            return;
+
+                        repeatHitObject.RepeatCount = proposedCount;
                         break;
 
                     case IHasEndTime endTimeHitObject: