From b06e70e546ca0a2d82ecfbce85f977a2a200fb28 Mon Sep 17 00:00:00 2001
From: Dean Herbert <pe@ppy.sh>
Date: Tue, 29 Oct 2019 15:27:08 +0900
Subject: [PATCH 1/2] Add failing test showing issue with day separator logic

---
 .../Online/TestSceneStandAloneChatDisplay.cs  | 20 ++++++++++++++++++-
 osu.Game/Overlays/Chat/DrawableChannel.cs     |  2 +-
 2 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/osu.Game.Tests/Visual/Online/TestSceneStandAloneChatDisplay.cs b/osu.Game.Tests/Visual/Online/TestSceneStandAloneChatDisplay.cs
index d973799405..01400bf1d9 100644
--- a/osu.Game.Tests/Visual/Online/TestSceneStandAloneChatDisplay.cs
+++ b/osu.Game.Tests/Visual/Online/TestSceneStandAloneChatDisplay.cs
@@ -9,6 +9,7 @@ using osuTK;
 using System;
 using System.Linq;
 using osu.Framework.Graphics.Containers;
+using osu.Game.Graphics.Containers;
 using osu.Game.Overlays.Chat;
 
 namespace osu.Game.Tests.Visual.Online
@@ -137,6 +138,17 @@ namespace osu.Game.Tests.Visual.Online
                         });
                 }, Channel.MAX_HISTORY / messages_per_call + 5);
 
+            AddAssert("Ensure no adjacent day separators", () =>
+            {
+                var indices = chatDisplay.FillFlow.OfType<DrawableChannel.DaySeparator>().Select(ds => chatDisplay.FillFlow.IndexOf(ds));
+
+                foreach (var i in indices)
+                    if (i < chatDisplay.FillFlow.Count && chatDisplay.FillFlow[i + 1] is DrawableChannel.DaySeparator)
+                        return false;
+
+                return true;
+            });
+
             AddUntilStep("ensure still scrolled to bottom", () => chatDisplay.ScrolledToBottom);
         }
 
@@ -147,7 +159,13 @@ namespace osu.Game.Tests.Visual.Online
             {
             }
 
-            public bool ScrolledToBottom => ((ScrollContainer<Drawable>)((Container)InternalChildren.OfType<DrawableChannel>().First().Child).Child).IsScrolledToEnd(1);
+            protected DrawableChannel DrawableChannel => InternalChildren.OfType<DrawableChannel>().First();
+
+            protected OsuScrollContainer ScrollContainer => (OsuScrollContainer)((Container)DrawableChannel.Child).Child;
+
+            public FillFlowContainer FillFlow => (FillFlowContainer)ScrollContainer.Child;
+
+            public bool ScrolledToBottom => ScrollContainer.IsScrolledToEnd(1);
         }
     }
 }
diff --git a/osu.Game/Overlays/Chat/DrawableChannel.cs b/osu.Game/Overlays/Chat/DrawableChannel.cs
index 9301daa9ff..636fafb5f2 100644
--- a/osu.Game/Overlays/Chat/DrawableChannel.cs
+++ b/osu.Game/Overlays/Chat/DrawableChannel.cs
@@ -142,7 +142,7 @@ namespace osu.Game.Overlays.Chat
 
         private void scrollToEnd() => ScheduleAfterChildren(() => scroll.ScrollToEnd());
 
-        protected class DaySeparator : Container
+        public class DaySeparator : Container
         {
             public float TextSize
             {

From 54befb6f8fdbdfe36e9f299b3df54782ff08cf7f Mon Sep 17 00:00:00 2001
From: Dean Herbert <pe@ppy.sh>
Date: Tue, 29 Oct 2019 15:45:41 +0900
Subject: [PATCH 2/2] Remove adjacent day separators

---
 osu.Game/Overlays/Chat/DrawableChannel.cs | 22 ++++++++++++++++++----
 1 file changed, 18 insertions(+), 4 deletions(-)

diff --git a/osu.Game/Overlays/Chat/DrawableChannel.cs b/osu.Game/Overlays/Chat/DrawableChannel.cs
index 636fafb5f2..427bd8dcde 100644
--- a/osu.Game/Overlays/Chat/DrawableChannel.cs
+++ b/osu.Game/Overlays/Chat/DrawableChannel.cs
@@ -108,11 +108,25 @@ namespace osu.Game.Overlays.Chat
             var staleMessages = chatLines.Where(c => c.LifetimeEnd == double.MaxValue).ToArray();
             int count = staleMessages.Length - Channel.MAX_HISTORY;
 
-            for (int i = 0; i < count; i++)
+            if (count > 0)
             {
-                var d = staleMessages[i];
-                scroll.OffsetScrollPosition(-d.DrawHeight);
-                d.Expire();
+                void expireAndAdjustScroll(Drawable d)
+                {
+                    scroll.OffsetScrollPosition(-d.DrawHeight);
+                    d.Expire();
+                }
+
+                for (int i = 0; i < count; i++)
+                    expireAndAdjustScroll(staleMessages[i]);
+
+                // remove all adjacent day separators after stale message removal
+                for (int i = 0; i < ChatLineFlow.Count - 1; i++)
+                {
+                    if (!(ChatLineFlow[i] is DaySeparator)) break;
+                    if (!(ChatLineFlow[i + 1] is DaySeparator)) break;
+
+                    expireAndAdjustScroll(ChatLineFlow[i]);
+                }
             }
 
             if (shouldScrollToEnd)