Merge branch 'master' into beatmap-card-basics

Directory.Build.props

@@ -16,7 +16,7 @@
     <EmbeddedResource Include="Resources\**\*.*" />
   </ItemGroup>
   <ItemGroup Label="Code Analysis">
-    <PackageReference Include="Microsoft.CodeAnalysis.BannedApiAnalyzers" Version="3.3.2" PrivateAssets="All" />
+    <PackageReference Include="Microsoft.CodeAnalysis.BannedApiAnalyzers" Version="3.3.3" PrivateAssets="All" />
     <AdditionalFiles Include="$(MSBuildThisFileDirectory)CodeAnalysis\BannedSymbols.txt" />
     <PackageReference Include="Microsoft.CodeAnalysis.NetAnalyzers" Version="5.0.3" PrivateAssets="All" />
   </ItemGroup>

Templates/Rulesets/ruleset-empty/osu.Game.Rulesets.EmptyFreeform.Tests/osu.Game.Rulesets.EmptyFreeform.Tests.csproj

@@ -10,7 +10,7 @@
     </PropertyGroup>
   <ItemGroup Label="Package References">
     <PackageReference Include="Appveyor.TestLogger" Version="2.0.0" />
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.11.0" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.0.0" />
     <PackageReference Include="NUnit" Version="3.13.2" />
     <PackageReference Include="NUnit3TestAdapter" Version="4.0.0" />
     <PackageReference Update="Microsoft.EntityFrameworkCore.Sqlite" Version="2.1.4" />

Templates/Rulesets/ruleset-example/osu.Game.Rulesets.Pippidon.Tests/osu.Game.Rulesets.Pippidon.Tests.csproj

@@ -10,7 +10,7 @@
   </PropertyGroup>
   <ItemGroup Label="Package References">
     <PackageReference Include="Appveyor.TestLogger" Version="2.0.0" />
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.11.0" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.0.0" />
     <PackageReference Include="NUnit" Version="3.13.2" />
     <PackageReference Include="NUnit3TestAdapter" Version="4.0.0" />
     <PackageReference Update="Microsoft.EntityFrameworkCore.Sqlite" Version="2.1.4" />

Templates/Rulesets/ruleset-scrolling-empty/osu.Game.Rulesets.EmptyScrolling.Tests/osu.Game.Rulesets.EmptyScrolling.Tests.csproj

@@ -10,7 +10,7 @@
   </PropertyGroup>
   <ItemGroup Label="Package References">
     <PackageReference Include="Appveyor.TestLogger" Version="2.0.0" />
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.11.0" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.0.0" />
     <PackageReference Include="NUnit" Version="3.13.2" />
     <PackageReference Include="NUnit3TestAdapter" Version="4.0.0" />
     <PackageReference Update="Microsoft.EntityFrameworkCore.Sqlite" Version="2.1.4" />

Templates/Rulesets/ruleset-scrolling-example/osu.Game.Rulesets.Pippidon.Tests/osu.Game.Rulesets.Pippidon.Tests.csproj

@@ -10,7 +10,7 @@
   </PropertyGroup>
   <ItemGroup Label="Package References">
     <PackageReference Include="Appveyor.TestLogger" Version="2.0.0" />
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.11.0" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.0.0" />
     <PackageReference Include="NUnit" Version="3.13.2" />
     <PackageReference Include="NUnit3TestAdapter" Version="4.0.0" />
     <PackageReference Update="Microsoft.EntityFrameworkCore.Sqlite" Version="2.1.4" />

osu.Android/OsuGameActivity.cs

@@ -20,6 +20,7 @@ namespace osu.Android
     [Activity(Theme = "@android:style/Theme.NoTitleBar", MainLauncher = true, ScreenOrientation = ScreenOrientation.FullUser, SupportsPictureInPicture = false, ConfigurationChanges = ConfigChanges.Orientation | ConfigChanges.ScreenSize, HardwareAccelerated = false, LaunchMode = LaunchMode.SingleInstance, Exported = true)]
     [IntentFilter(new[] { Intent.ActionView }, Categories = new[] { Intent.CategoryDefault }, DataScheme = "content", DataPathPattern = ".*\\\\.osz", DataHost = "*", DataMimeType = "*/*")]
     [IntentFilter(new[] { Intent.ActionView }, Categories = new[] { Intent.CategoryDefault }, DataScheme = "content", DataPathPattern = ".*\\\\.osk", DataHost = "*", DataMimeType = "*/*")]
+    [IntentFilter(new[] { Intent.ActionView }, Categories = new[] { Intent.CategoryDefault }, DataScheme = "content", DataPathPattern = ".*\\\\.osr", DataHost = "*", DataMimeType = "*/*")]
     [IntentFilter(new[] { Intent.ActionView }, Categories = new[] { Intent.CategoryDefault }, DataScheme = "content", DataMimeType = "application/x-osu-beatmap-archive")]
     [IntentFilter(new[] { Intent.ActionView }, Categories = new[] { Intent.CategoryDefault }, DataScheme = "content", DataMimeType = "application/x-osu-skin-archive")]
     [IntentFilter(new[] { Intent.ActionView }, Categories = new[] { Intent.CategoryDefault }, DataScheme = "content", DataMimeType = "application/x-osu-replay")]

osu.Game.Rulesets.Catch.Tests/osu.Game.Rulesets.Catch.Tests.csproj

@@ -2,7 +2,7 @@
   <Import Project="..\osu.TestProject.props" />
   <ItemGroup Label="Package References">
     <PackageReference Include="Appveyor.TestLogger" Version="2.0.0" />
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.11.0" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.0.0" />
     <PackageReference Include="NUnit" Version="3.13.2" />
     <PackageReference Include="NUnit3TestAdapter" Version="4.0.0" />
     <PackageReference Update="Microsoft.EntityFrameworkCore.Sqlite" Version="2.1.4" />

osu.Game.Rulesets.Catch/Mods/CatchModAutoplay.cs

@@ -14,7 +14,7 @@ namespace osu.Game.Rulesets.Catch.Mods
     {
         public override Score CreateReplayScore(IBeatmap beatmap, IReadOnlyList<Mod> mods) => new Score
         {
-            ScoreInfo = new ScoreInfo { User = new User { Username = "osu!salad!" } },
+            ScoreInfo = new ScoreInfo { User = new User { Username = "osu!salad" } },
             Replay = new CatchAutoGenerator(beatmap).Generate(),
         };
     }

osu.Game.Rulesets.Catch/Mods/CatchModCinema.cs

@@ -15,7 +15,7 @@ namespace osu.Game.Rulesets.Catch.Mods
     {
         public override Score CreateReplayScore(IBeatmap beatmap, IReadOnlyList<Mod> mods) => new Score
         {
-            ScoreInfo = new ScoreInfo { User = new User { Username = "osu!salad!" } },
+            ScoreInfo = new ScoreInfo { User = new User { Username = "osu!salad" } },
             Replay = new CatchAutoGenerator(beatmap).Generate(),
         };
     }

osu.Game.Rulesets.Mania.Tests/osu.Game.Rulesets.Mania.Tests.csproj

@@ -2,7 +2,7 @@
   <Import Project="..\osu.TestProject.props" />
   <ItemGroup Label="Package References">
     <PackageReference Include="Appveyor.TestLogger" Version="2.0.0" />
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.11.0" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.0.0" />
     <PackageReference Include="NUnit" Version="3.13.2" />
     <PackageReference Include="NUnit3TestAdapter" Version="4.0.0" />
     <PackageReference Update="Microsoft.EntityFrameworkCore.Sqlite" Version="2.1.4" />

osu.Game.Rulesets.Mania/Mods/ManiaModAutoplay.cs

@@ -15,7 +15,7 @@ namespace osu.Game.Rulesets.Mania.Mods
     {
         public override Score CreateReplayScore(IBeatmap beatmap, IReadOnlyList<Mod> mods) => new Score
         {
-            ScoreInfo = new ScoreInfo { User = new User { Username = "osu!topus!" } },
+            ScoreInfo = new ScoreInfo { User = new User { Username = "osu!topus" } },
             Replay = new ManiaAutoGenerator((ManiaBeatmap)beatmap).Generate(),
         };
     }

osu.Game.Rulesets.Mania/Mods/ManiaModCinema.cs

@@ -16,7 +16,7 @@ namespace osu.Game.Rulesets.Mania.Mods
     {
         public override Score CreateReplayScore(IBeatmap beatmap, IReadOnlyList<Mod> mods) => new Score
         {
-            ScoreInfo = new ScoreInfo { User = new User { Username = "osu!topus!" } },
+            ScoreInfo = new ScoreInfo { User = new User { Username = "osu!topus" } },
             Replay = new ManiaAutoGenerator((ManiaBeatmap)beatmap).Generate(),
         };
     }

osu.Game.Rulesets.Osu.Tests/OsuDifficultyCalculatorTest.cs

@@ -15,13 +15,13 @@ namespace osu.Game.Rulesets.Osu.Tests
     {
         protected override string ResourceAssembly => "osu.Game.Rulesets.Osu";
 
-        [TestCase(6.5867229481955389d, "diffcalc-test")]
+        [TestCase(6.5295339534769958d, "diffcalc-test")]
-        [TestCase(1.0416315570967911d, "zero-length-sliders")]
+        [TestCase(1.1514260533755143d, "zero-length-sliders")]
         public void Test(double expected, string name)
             => base.Test(expected, name);
 
-        [TestCase(8.2730989071947896d, "diffcalc-test")]
+        [TestCase(9.047752485219954d, "diffcalc-test")]
-        [TestCase(1.2726413186221039d, "zero-length-sliders")]
+        [TestCase(1.3985711787077566d, "zero-length-sliders")]
         public void TestClockRateAdjusted(double expected, string name)
             => Test(expected, name, new OsuModDoubleTime());
 

osu.Game.Rulesets.Osu.Tests/TestSceneNoSpinnerStacking.cs

@@ -0,0 +1,34 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using NUnit.Framework;
+using osu.Game.Beatmaps;
+using osu.Game.Rulesets.Osu.Objects;
+using osuTK;
+
+namespace osu.Game.Rulesets.Osu.Tests
+{
+    [TestFixture]
+    public class TestSceneNoSpinnerStacking : TestSceneOsuPlayer
+    {
+        protected override IBeatmap CreateBeatmap(RulesetInfo ruleset)
+        {
+            var beatmap = new Beatmap
+            {
+                BeatmapInfo = new BeatmapInfo
+                {
+                    BaseDifficulty = new BeatmapDifficulty { OverallDifficulty = 10 },
+                    Ruleset = ruleset
+                }
+            };
+
+            for (int i = 0; i < 512; i++)
+            {
+                if (i % 32 < 20)
+                    beatmap.HitObjects.Add(new Spinner { Position = new Vector2(256, 192), StartTime = i * 200, EndTime = (i * 200) + 100 });
+            }
+
+            return beatmap;
+        }
+    }
+}

osu.Game.Rulesets.Osu.Tests/osu.Game.Rulesets.Osu.Tests.csproj

@@ -2,7 +2,7 @@
   <Import Project="..\osu.TestProject.props" />
   <ItemGroup Label="Package References">
     <PackageReference Include="Appveyor.TestLogger" Version="2.0.0" />
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.11.0" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.0.0" />
     <PackageReference Include="Moq" Version="4.16.1" />
     <PackageReference Include="NUnit" Version="3.13.2" />
     <PackageReference Include="NUnit3TestAdapter" Version="4.0.0" />

osu.Game.Rulesets.Osu/Difficulty/Preprocessing/OsuDifficultyHitObject.cs

@@ -12,20 +12,21 @@ namespace osu.Game.Rulesets.Osu.Difficulty.Preprocessing
 {
     public class OsuDifficultyHitObject : DifficultyHitObject
     {
-        private const int normalized_radius = 52;
+        private const int normalized_radius = 50; // Change radius to 50 to make 100 the diameter. Easier for mental maths.
+        private const int min_delta_time = 25;
 
         protected new OsuHitObject BaseObject => (OsuHitObject)base.BaseObject;
 
-        /// <summary>
-        /// Milliseconds elapsed since the start time of the previous <see cref="OsuDifficultyHitObject"/>, with a minimum of 25ms to account for simultaneous <see cref="OsuDifficultyHitObject"/>s.
-        /// </summary>
-        public double StrainTime { get; private set; }
-
         /// <summary>
         /// Normalized distance from the end position of the previous <see cref="OsuDifficultyHitObject"/> to the start position of this <see cref="OsuDifficultyHitObject"/>.
         /// </summary>
         public double JumpDistance { get; private set; }
 
+        /// <summary>
+        /// Minimum distance from the end position of the previous <see cref="OsuDifficultyHitObject"/> to the start position of this <see cref="OsuDifficultyHitObject"/>.
+        /// </summary>
+        public double MovementDistance { get; private set; }
+
         /// <summary>
         /// Normalized distance between the start and end position of the previous <see cref="OsuDifficultyHitObject"/>.
         /// </summary>
@@ -37,6 +38,21 @@ namespace osu.Game.Rulesets.Osu.Difficulty.Preprocessing
         /// </summary>
         public double? Angle { get; private set; }
 
+        /// <summary>
+        /// Milliseconds elapsed since the end time of the previous <see cref="OsuDifficultyHitObject"/>, with a minimum of 25ms.
+        /// </summary>
+        public double MovementTime { get; private set; }
+
+        /// <summary>
+        /// Milliseconds elapsed since the start time of the previous <see cref="OsuDifficultyHitObject"/> to the end time of the same previous <see cref="OsuDifficultyHitObject"/>, with a minimum of 25ms.
+        /// </summary>
+        public double TravelTime { get; private set; }
+
+        /// <summary>
+        /// Milliseconds elapsed since the start time of the previous <see cref="OsuDifficultyHitObject"/>, with a minimum of 25ms.
+        /// </summary>
+        public readonly double StrainTime;
+
         private readonly OsuHitObject lastLastObject;
         private readonly OsuHitObject lastObject;
 
@@ -46,13 +62,13 @@ namespace osu.Game.Rulesets.Osu.Difficulty.Preprocessing
             this.lastLastObject = (OsuHitObject)lastLastObject;
             this.lastObject = (OsuHitObject)lastObject;
 
-            setDistances();
+            // Capped to 25ms to prevent difficulty calculation breaking from simultaneous objects.
+            StrainTime = Math.Max(DeltaTime, min_delta_time);
 
-            // Capped to 25ms to prevent difficulty calculation breaking from simulatenous objects.
+            setDistances(clockRate);
-            StrainTime = Math.Max(DeltaTime, 25);
         }
 
-        private void setDistances()
+        private void setDistances(double clockRate)
         {
             // We don't need to calculate either angle or distance when one of the last->curr objects is a spinner
             if (BaseObject is Spinner || lastObject is Spinner)
@@ -67,15 +83,29 @@ namespace osu.Game.Rulesets.Osu.Difficulty.Preprocessing
                 scalingFactor *= 1 + smallCircleBonus;
             }
 
+            Vector2 lastCursorPosition = getEndCursorPosition(lastObject);
+            JumpDistance = (BaseObject.StackedPosition * scalingFactor - lastCursorPosition * scalingFactor).Length;
+
             if (lastObject is Slider lastSlider)
             {
                 computeSliderCursorPosition(lastSlider);
                 TravelDistance = lastSlider.LazyTravelDistance * scalingFactor;
+                TravelTime = Math.Max(lastSlider.LazyTravelTime / clockRate, min_delta_time);
+                MovementTime = Math.Max(StrainTime - TravelTime, min_delta_time);
+
+                // Jump distance from the slider tail to the next object, as opposed to the lazy position of JumpDistance.
+                float tailJumpDistance = Vector2.Subtract(lastSlider.TailCircle.StackedPosition, BaseObject.StackedPosition).Length * scalingFactor;
+
+                // For hitobjects which continue in the direction of the slider, the player will normally follow through the slider,
+                // such that they're not jumping from the lazy position but rather from very close to (or the end of) the slider.
+                // In such cases, a leniency is applied by also considering the jump distance from the tail of the slider, and taking the minimum jump distance.
+                MovementDistance = Math.Min(JumpDistance, tailJumpDistance);
+            }
+            else
+            {
+                MovementTime = StrainTime;
+                MovementDistance = JumpDistance;
             }
-
-            Vector2 lastCursorPosition = getEndCursorPosition(lastObject);
-
-            JumpDistance = (BaseObject.StackedPosition * scalingFactor - lastCursorPosition * scalingFactor).Length;
 
             if (lastLastObject != null && !(lastLastObject is Spinner))
             {
@@ -98,7 +128,7 @@ namespace osu.Game.Rulesets.Osu.Difficulty.Preprocessing
 
             slider.LazyEndPosition = slider.StackedPosition;
 
-            float approxFollowCircleRadius = (float)(slider.Radius * 3);
+            float followCircleRadius = (float)(slider.Radius * 2.4);
             var computeVertex = new Action<double>(t =>
             {
                 double progress = (t - slider.StartTime) / slider.SpanDuration;
@@ -111,11 +141,13 @@ namespace osu.Game.Rulesets.Osu.Difficulty.Preprocessing
                 var diff = slider.StackedPosition + slider.Path.PositionAt(progress) - slider.LazyEndPosition.Value;
                 float dist = diff.Length;
 
-                if (dist > approxFollowCircleRadius)
+                slider.LazyTravelTime = t - slider.StartTime;
+
+                if (dist > followCircleRadius)
                 {
                     // The cursor would be outside the follow circle, we need to move it
                     diff.Normalize(); // Obtain direction of diff
-                    dist -= approxFollowCircleRadius;
+                    dist -= followCircleRadius;
                     slider.LazyEndPosition += diff * dist;
                     slider.LazyTravelDistance += dist;
                 }

osu.Game.Rulesets.Osu/Difficulty/Skills/Aim.cs

@@ -14,53 +14,96 @@ namespace osu.Game.Rulesets.Osu.Difficulty.Skills
     /// </summary>
     public class Aim : OsuStrainSkill
     {
-        private const double angle_bonus_begin = Math.PI / 3;
-        private const double timing_threshold = 107;
-
         public Aim(Mod[] mods)
             : base(mods)
         {
         }
 
+        protected override int HistoryLength => 2;
+
+        private const double wide_angle_multiplier = 1.5;
+        private const double acute_angle_multiplier = 2.0;
+
         private double currentStrain = 1;
 
-        private double skillMultiplier => 26.25;
+        private double skillMultiplier => 23.25;
         private double strainDecayBase => 0.15;
 
         private double strainValueOf(DifficultyHitObject current)
         {
-            if (current.BaseObject is Spinner)
+            if (current.BaseObject is Spinner || Previous.Count <= 1 || Previous[0].BaseObject is Spinner)
                 return 0;
 
-            var osuCurrent = (OsuDifficultyHitObject)current;
+            var osuCurrObj = (OsuDifficultyHitObject)current;
+            var osuLastObj = (OsuDifficultyHitObject)Previous[0];
+            var osuLastLastObj = (OsuDifficultyHitObject)Previous[1];
 
-            double aimStrain = 0;
+            // Calculate the velocity to the current hitobject, which starts with a base distance / time assuming the last object is a hitcircle.
+            double currVelocity = osuCurrObj.JumpDistance / osuCurrObj.StrainTime;
 
-            if (Previous.Count > 0)
+            // But if the last object is a slider, then we extend the travel velocity through the slider into the current object.
+            if (osuLastObj.BaseObject is Slider)
             {
-                var osuPrevious = (OsuDifficultyHitObject)Previous[0];
+                double movementVelocity = osuCurrObj.MovementDistance / osuCurrObj.MovementTime; // calculate the movement velocity from slider end to current object
+                double travelVelocity = osuCurrObj.TravelDistance / osuCurrObj.TravelTime; // calculate the slider velocity from slider head to slider end.
 
-                if (osuCurrent.Angle != null && osuCurrent.Angle.Value > angle_bonus_begin)
+                currVelocity = Math.Max(currVelocity, movementVelocity + travelVelocity); // take the larger total combined velocity.
+            }
+
+            // As above, do the same for the previous hitobject.
+            double prevVelocity = osuLastObj.JumpDistance / osuLastObj.StrainTime;
+
+            if (osuLastLastObj.BaseObject is Slider)
+            {
+                double movementVelocity = osuLastObj.MovementDistance / osuLastObj.MovementTime;
+                double travelVelocity = osuLastObj.TravelDistance / osuLastObj.TravelTime;
+
+                prevVelocity = Math.Max(prevVelocity, movementVelocity + travelVelocity);
+            }
+
+            double angleBonus = 0;
+            double aimStrain = currVelocity; // Start strain with regular velocity.
+
+            if (Math.Max(osuCurrObj.StrainTime, osuLastObj.StrainTime) < 1.25 * Math.Min(osuCurrObj.StrainTime, osuLastObj.StrainTime)) // If rhythms are the same.
+            {
+                if (osuCurrObj.Angle != null && osuLastObj.Angle != null && osuLastLastObj.Angle != null)
                 {
-                    const double scale = 90;
+                    double currAngle = osuCurrObj.Angle.Value;
+                    double lastAngle = osuLastObj.Angle.Value;
+                    double lastLastAngle = osuLastLastObj.Angle.Value;
 
-                    double angleBonus = Math.Sqrt(
+                    // Rewarding angles, take the smaller velocity as base.
-                        Math.Max(osuPrevious.JumpDistance - scale, 0)
+                    angleBonus = Math.Min(currVelocity, prevVelocity);
-                        * Math.Pow(Math.Sin(osuCurrent.Angle.Value - angle_bonus_begin), 2)
+
-                        * Math.Max(osuCurrent.JumpDistance - scale, 0));
+                    double wideAngleBonus = calcWideAngleBonus(currAngle);
-                    aimStrain = 1.4 * applyDiminishingExp(Math.Max(0, angleBonus)) / Math.Max(timing_threshold, osuPrevious.StrainTime);
+                    double acuteAngleBonus = calcAcuteAngleBonus(currAngle);
+
+                    if (osuCurrObj.StrainTime > 100) // Only buff deltaTime exceeding 300 bpm 1/2.
+                        acuteAngleBonus = 0;
+                    else
+                    {
+                        acuteAngleBonus *= calcAcuteAngleBonus(lastAngle) // Multiply by previous angle, we don't want to buff unless this is a wiggle type pattern.
+                                           * Math.Min(angleBonus, 125 / osuCurrObj.StrainTime) // The maximum velocity we buff is equal to 125 / strainTime
+                                           * Math.Pow(Math.Sin(Math.PI / 2 * Math.Min(1, (100 - osuCurrObj.StrainTime) / 25)), 2) // scale buff from 150 bpm 1/4 to 200 bpm 1/4
+                                           * Math.Pow(Math.Sin(Math.PI / 2 * (Math.Clamp(osuCurrObj.JumpDistance, 50, 100) - 50) / 50), 2); // Buff distance exceeding 50 (radius) up to 100 (diameter).
+                    }
+
+                    wideAngleBonus *= angleBonus * (1 - Math.Min(wideAngleBonus, Math.Pow(calcWideAngleBonus(lastAngle), 3))); // Penalize wide angles if they're repeated, reducing the penalty as the lastAngle gets more acute.
+                    acuteAngleBonus *= 0.5 + 0.5 * (1 - Math.Min(acuteAngleBonus, Math.Pow(calcAcuteAngleBonus(lastLastAngle), 3))); // Penalize acute angles if they're repeated, reducing the penalty as the lastLastAngle gets more obtuse.
+
+                    angleBonus = acuteAngleBonus * acute_angle_multiplier + wideAngleBonus * wide_angle_multiplier; // add the angle buffs together.
                 }
             }
 
-            double jumpDistanceExp = applyDiminishingExp(osuCurrent.JumpDistance);
+            aimStrain += angleBonus; // Add in angle bonus.
-            double travelDistanceExp = applyDiminishingExp(osuCurrent.TravelDistance);
 
-            return Math.Max(
+            return aimStrain;
-                aimStrain + (jumpDistanceExp + travelDistanceExp + Math.Sqrt(travelDistanceExp * jumpDistanceExp)) / Math.Max(osuCurrent.StrainTime, timing_threshold),
-                (Math.Sqrt(travelDistanceExp * jumpDistanceExp) + jumpDistanceExp + travelDistanceExp) / osuCurrent.StrainTime
-            );
         }
 
+        private double calcWideAngleBonus(double angle) => Math.Pow(Math.Sin(3.0 / 4 * (Math.Min(5.0 / 6 * Math.PI, Math.Max(Math.PI / 6, angle)) - Math.PI / 6)), 2);
+
+        private double calcAcuteAngleBonus(double angle) => 1 - calcWideAngleBonus(angle);
+
         private double applyDiminishingExp(double val) => Math.Pow(val, 0.99);
 
         private double strainDecay(double ms) => Math.Pow(strainDecayBase, ms / 1000);

osu.Game.Rulesets.Osu/Objects/OsuHitObject.cs

@@ -59,7 +59,7 @@ namespace osu.Game.Rulesets.Osu.Objects
             set => StackHeightBindable.Value = value;
         }
 
-        public Vector2 StackOffset => new Vector2(StackHeight * Scale * -6.4f);
+        public virtual Vector2 StackOffset => new Vector2(StackHeight * Scale * -6.4f);
 
         public double Radius => OBJECT_RADIUS * Scale;
 

osu.Game.Rulesets.Osu/Objects/Slider.cs

@@ -79,6 +79,12 @@ namespace osu.Game.Rulesets.Osu.Objects
         /// </summary>
         internal float LazyTravelDistance;
 
+        /// <summary>
+        /// The time taken by the cursor upon completion of this <see cref="Slider"/> if it was hit
+        /// with as few movements as possible. This is set and used by difficulty calculation.
+        /// </summary>
+        internal double LazyTravelTime;
+
         public IList<IList<HitSampleInfo>> NodeSamples { get; set; } = new List<IList<HitSampleInfo>>();
 
         [JsonIgnore]

osu.Game.Rulesets.Osu/Objects/Spinner.cs

@@ -8,6 +8,7 @@ using osu.Game.Rulesets.Judgements;
 using osu.Game.Rulesets.Objects.Types;
 using osu.Game.Rulesets.Osu.Judgements;
 using osu.Game.Rulesets.Scoring;
+using osuTK;
 
 namespace osu.Game.Rulesets.Osu.Objects
 {
@@ -31,6 +32,8 @@ namespace osu.Game.Rulesets.Osu.Objects
         /// </summary>
         public int MaximumBonusSpins { get; protected set; } = 1;
 
+        public override Vector2 StackOffset => Vector2.Zero;
+
         protected override void ApplyDefaultsToSelf(ControlPointInfo controlPointInfo, IBeatmapDifficultyInfo difficulty)
         {
             base.ApplyDefaultsToSelf(controlPointInfo, difficulty);

osu.Game.Rulesets.Taiko.Tests/osu.Game.Rulesets.Taiko.Tests.csproj

@@ -2,7 +2,7 @@
   <Import Project="..\osu.TestProject.props" />
   <ItemGroup Label="Package References">
     <PackageReference Include="Appveyor.TestLogger" Version="2.0.0" />
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.11.0" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.0.0" />
     <PackageReference Include="NUnit" Version="3.13.2" />
     <PackageReference Include="NUnit3TestAdapter" Version="4.0.0" />
     <PackageReference Update="Microsoft.EntityFrameworkCore.Sqlite" Version="2.1.4" />

osu.Game.Tests/Skins/IO/ImportSkinTest.cs

@@ -38,6 +38,15 @@ namespace osu.Game.Tests.Skins.IO
             assertCorrectMetadata(import1, "test skin [skin]", "skinner", osu);
         });
 
+        [Test]
+        public Task TestSingleImportMissingSectionHeader() => runSkinTest(async osu =>
+        {
+            var import1 = await loadSkinIntoOsu(osu, new ZipArchiveReader(createOskWithIni("test skin", "skinner", includeSectionHeader: false), "skin.osk"));
+
+            // When the import filename doesn't match, it should be appended (and update the skin.ini).
+            assertCorrectMetadata(import1, "test skin [skin]", "skinner", osu);
+        });
+
         [Test]
         public Task TestSingleImportMatchingFilename() => runSkinTest(async osu =>
         {
@@ -199,21 +208,23 @@ namespace osu.Game.Tests.Skins.IO
             return zipStream;
         }
 
-        private MemoryStream createOskWithIni(string name, string author, bool makeUnique = false, string iniFilename = @"skin.ini")
+        private MemoryStream createOskWithIni(string name, string author, bool makeUnique = false, string iniFilename = @"skin.ini", bool includeSectionHeader = true)
         {
             var zipStream = new MemoryStream();
             using var zip = ZipArchive.Create();
-            zip.AddEntry(iniFilename, generateSkinIni(name, author, makeUnique));
+            zip.AddEntry(iniFilename, generateSkinIni(name, author, makeUnique, includeSectionHeader));
             zip.SaveTo(zipStream);
             return zipStream;
         }
 
-        private MemoryStream generateSkinIni(string name, string author, bool makeUnique = true)
+        private MemoryStream generateSkinIni(string name, string author, bool makeUnique = true, bool includeSectionHeader = true)
         {
             var stream = new MemoryStream();
             var writer = new StreamWriter(stream);
 
-            writer.WriteLine("[General]");
+            if (includeSectionHeader)
+                writer.WriteLine("[General]");
+
             writer.WriteLine($"Name: {name}");
             writer.WriteLine($"Author: {author}");
 

osu.Game.Tests/Visual/Multiplayer/TestSceneMultiplayer.cs

@@ -231,6 +231,9 @@ namespace osu.Game.Tests.Visual.Multiplayer
                     }
                 }
             });
+
+            AddAssert("Check participant count correct", () => client.APIRoom?.ParticipantCount.Value == 1);
+            AddAssert("Check participant list contains user", () => client.APIRoom?.RecentParticipants.Count(u => u.Id == API.LocalUser.Value.Id) == 1);
         }
 
         [Test]
@@ -290,6 +293,9 @@ namespace osu.Game.Tests.Visual.Multiplayer
 
             AddUntilStep("wait for room open", () => this.ChildrenOfType<MultiplayerMatchSubScreen>().FirstOrDefault()?.IsLoaded == true);
             AddUntilStep("wait for join", () => client.Room != null);
+
+            AddAssert("Check participant count correct", () => client.APIRoom?.ParticipantCount.Value == 1);
+            AddAssert("Check participant list contains user", () => client.APIRoom?.RecentParticipants.Count(u => u.Id == API.LocalUser.Value.Id) == 1);
         }
 
         [Test]

osu.Game.Tests/Visual/Multiplayer/TestSceneMultiplayerParticipantsList.cs

@@ -45,11 +45,11 @@ namespace osu.Game.Tests.Visual.Multiplayer
         }
 
         [Test]
-        public void TestAddNullUser()
+        public void TestAddUnresolvedUser()
         {
             AddAssert("one unique panel", () => this.ChildrenOfType<ParticipantPanel>().Select(p => p.User).Distinct().Count() == 1);
 
-            AddStep("add non-resolvable user", () => Client.AddNullUser());
+            AddStep("add non-resolvable user", () => Client.TestAddUnresolvedUser());
             AddAssert("null user added", () => Client.Room.AsNonNull().Users.Count(u => u.User == null) == 1);
 
             AddUntilStep("two unique panels", () => this.ChildrenOfType<ParticipantPanel>().Select(p => p.User).Distinct().Count() == 2);

osu.Game.Tests/osu.Game.Tests.csproj

@@ -3,7 +3,7 @@
   <ItemGroup Label="Package References">
     <PackageReference Include="Appveyor.TestLogger" Version="2.0.0" />
     <PackageReference Include="DeepEqual" Version="2.0.0" />
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.11.0" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.0.0" />
     <PackageReference Include="Nito.AsyncEx" Version="5.1.2" />
     <PackageReference Include="NUnit" Version="3.13.2" />
     <PackageReference Include="NUnit3TestAdapter" Version="4.0.0" />

osu.Game.Tournament.Tests/osu.Game.Tournament.Tests.csproj

@@ -5,7 +5,7 @@
   </PropertyGroup>
   <ItemGroup Label="Package References">
     <PackageReference Include="Appveyor.TestLogger" Version="2.0.0" />
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.11.0" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.0.0" />
     <PackageReference Include="NUnit" Version="3.13.2" />
     <PackageReference Include="NUnit3TestAdapter" Version="4.0.0" />
   </ItemGroup>

osu.Game/Beatmaps/BeatmapDifficultyCache.cs

@@ -131,7 +131,7 @@ namespace osu.Game.Beatmaps
             var localRulesetInfo = rulesetInfo as RulesetInfo;
 
             // Difficulty can only be computed if the beatmap and ruleset are locally available.
-            if (localBeatmapInfo == null || localRulesetInfo == null)
+            if (localBeatmapInfo == null || localBeatmapInfo.ID == 0 || localRulesetInfo == null)
             {
                 // If not, fall back to the existing star difficulty (e.g. from an online source).
                 return Task.FromResult(new StarDifficulty(beatmapInfo.StarRating, (beatmapInfo as IBeatmapOnlineInfo)?.MaxCombo ?? 0));

osu.Game/Beatmaps/BeatmapManager.cs

@@ -249,6 +249,23 @@ namespace osu.Game.Beatmaps
 
         public IBindable<WeakReference<ArchiveDownloadRequest<BeatmapSetInfo>>> DownloadFailed => beatmapModelDownloader.DownloadFailed;
 
+        // Temporary method until this class supports IBeatmapSetInfo or otherwise.
+        public bool Download(IBeatmapSetInfo model, bool minimiseDownloadSize = false)
+        {
+            return beatmapModelDownloader.Download(new BeatmapSetInfo
+            {
+                OnlineBeatmapSetID = model.OnlineID,
+                Metadata = new BeatmapMetadata
+                {
+                    Title = model.Metadata?.Title,
+                    Artist = model.Metadata?.Artist,
+                    TitleUnicode = model.Metadata?.TitleUnicode,
+                    ArtistUnicode = model.Metadata?.ArtistUnicode,
+                    Author = new User { Username = model.Metadata?.Author },
+                }
+            }, minimiseDownloadSize);
+        }
+
         public bool Download(BeatmapSetInfo model, bool minimiseDownloadSize = false)
         {
             return beatmapModelDownloader.Download(model, minimiseDownloadSize);

osu.Game/Beatmaps/Drawables/DifficultyIcon.cs

@@ -60,8 +60,9 @@ namespace osu.Game.Beatmaps.Drawables
         /// <param name="ruleset">The ruleset to show the difficulty with.</param>
         /// <param name="mods">The mods to show the difficulty with.</param>
         /// <param name="shouldShowTooltip">Whether to display a tooltip when hovered.</param>
-        public DifficultyIcon([NotNull] IBeatmapInfo beatmapInfo, [CanBeNull] IRulesetInfo ruleset, [CanBeNull] IReadOnlyList<Mod> mods, bool shouldShowTooltip = true)
+        /// <param name="performBackgroundDifficultyLookup">Whether to perform difficulty lookup (including calculation if necessary).</param>
-            : this(beatmapInfo, shouldShowTooltip)
+        public DifficultyIcon([NotNull] IBeatmapInfo beatmapInfo, [CanBeNull] IRulesetInfo ruleset, [CanBeNull] IReadOnlyList<Mod> mods, bool shouldShowTooltip = true, bool performBackgroundDifficultyLookup = true)
+            : this(beatmapInfo, shouldShowTooltip, performBackgroundDifficultyLookup)
         {
             this.ruleset = ruleset ?? beatmapInfo.Ruleset;
             this.mods = mods ?? Array.Empty<Mod>();

osu.Game/Beatmaps/Formats/LegacyDecoder.cs

@@ -27,7 +27,7 @@ namespace osu.Game.Beatmaps.Formats
 
         protected override void ParseStreamInto(LineBufferedReader stream, T output)
         {
-            Section section = Section.None;
+            Section section = Section.General;
 
             string line;
 
@@ -47,10 +47,7 @@ namespace osu.Game.Beatmaps.Formats
                 if (line.StartsWith('[') && line.EndsWith(']'))
                 {
                     if (!Enum.TryParse(line[1..^1], out section))
-                    {
                         Logger.Log($"Unknown section \"{line}\" in \"{output}\"");
-                        section = Section.None;
-                    }
 
                     OnBeginNewSection(section);
                     continue;
@@ -148,7 +145,6 @@ namespace osu.Game.Beatmaps.Formats
 
         protected enum Section
         {
-            None,
             General,
             Editor,
             Metadata,

osu.Game/Online/API/APIRequest.cs

@@ -107,7 +107,8 @@ namespace osu.Game.Online.API
             WebRequest = CreateWebRequest();
             WebRequest.Failed += Fail;
             WebRequest.AllowRetryOnTimeout = false;
-            WebRequest.AddHeader("Authorization", $"Bearer {API.AccessToken}");
+            if (!string.IsNullOrEmpty(API.AccessToken))
+                WebRequest.AddHeader("Authorization", $"Bearer {API.AccessToken}");
 
             if (isFailing) return;
 

osu.Game/Online/API/Requests/Responses/APIScoreInfo.cs

@@ -37,6 +37,7 @@ namespace osu.Game.Online.API.Requests.Responses
         public DateTimeOffset Date { get; set; }
 
         [JsonProperty(@"beatmap")]
+        [CanBeNull]
         public APIBeatmap Beatmap { get; set; }
 
         [JsonProperty("accuracy")]
@@ -46,6 +47,7 @@ namespace osu.Game.Online.API.Requests.Responses
         public double? PP { get; set; }
 
         [JsonProperty(@"beatmapset")]
+        [CanBeNull]
         public APIBeatmapSet BeatmapSet
         {
             set
@@ -96,7 +98,7 @@ namespace osu.Game.Online.API.Requests.Responses
             {
                 TotalScore = TotalScore,
                 MaxCombo = MaxCombo,
-                BeatmapInfo = Beatmap.ToBeatmapInfo(rulesets),
+                BeatmapInfo = Beatmap?.ToBeatmapInfo(rulesets),
                 User = User,
                 Accuracy = Accuracy,
                 OnlineScoreID = OnlineID,

osu.Game/Online/Multiplayer/MultiplayerClient.cs

@@ -148,6 +148,10 @@ namespace osu.Game.Online.Multiplayer
                 {
                     Room = joinedRoom;
                     APIRoom = room;
+
+                    Debug.Assert(LocalUser != null);
+                    addUserToAPIRoom(LocalUser);
+
                     foreach (var user in joinedRoom.Users)
                         updateUserPlayingState(user.UserID, user.State);
 
@@ -372,6 +376,8 @@ namespace osu.Game.Online.Multiplayer
 
                 Room.Users.Add(user);
 
+                addUserToAPIRoom(user);
+
                 UserJoined?.Invoke(user);
                 RoomUpdated?.Invoke();
             });
@@ -391,6 +397,18 @@ namespace osu.Game.Online.Multiplayer
             return handleUserLeft(user, UserKicked);
         }
 
+        private void addUserToAPIRoom(MultiplayerRoomUser user)
+        {
+            Debug.Assert(APIRoom != null);
+
+            APIRoom.RecentParticipants.Add(user.User ?? new User
+            {
+                Id = user.UserID,
+                Username = "[Unresolved]"
+            });
+            APIRoom.ParticipantCount.Value++;
+        }
+
         private Task handleUserLeft(MultiplayerRoomUser user, Action<MultiplayerRoomUser>? callback)
         {
             if (Room == null)
@@ -404,6 +422,10 @@ namespace osu.Game.Online.Multiplayer
                 Room.Users.Remove(user);
                 PlayingUserIds.Remove(user.UserID);
 
+                Debug.Assert(APIRoom != null);
+                APIRoom.RecentParticipants.RemoveAll(u => u.Id == user.UserID);
+                APIRoom.ParticipantCount.Value--;
+
                 callback?.Invoke(user);
                 RoomUpdated?.Invoke();
             }, false);

osu.Game/Online/Rooms/OnlinePlayBeatmapAvailabilityTracker.cs

@@ -53,7 +53,10 @@ namespace osu.Game.Online.Rooms
                 downloadTracker?.RemoveAndDisposeImmediately();
 
                 downloadTracker = new BeatmapDownloadTracker(item.NewValue.Beatmap.Value.BeatmapSet);
-                downloadTracker.State.BindValueChanged(_ => updateAvailability());
+
+                AddInternal(downloadTracker);
+
+                downloadTracker.State.BindValueChanged(_ => updateAvailability(), true);
                 downloadTracker.Progress.BindValueChanged(_ =>
                 {
                     if (downloadTracker.State.Value != DownloadState.Downloading)
@@ -63,9 +66,7 @@ namespace osu.Game.Online.Rooms
                     // we don't want to flood the network with this, so rate limit how often we send progress updates.
                     if (progressUpdate?.Completed != false)
                         progressUpdate = Scheduler.AddDelayed(updateAvailability, progressUpdate == null ? 0 : 500);
-                });
+                }, true);
-
-                AddInternal(downloadTracker);
             }, true);
         }
 

osu.Game/Online/Rooms/SubmitRoomScoreRequest.cs

@@ -5,6 +5,7 @@ using System.Net.Http;
 using Newtonsoft.Json;
 using osu.Framework.IO.Network;
 using osu.Game.Online.API;
+using osu.Game.Online.Solo;
 using osu.Game.Scoring;
 
 namespace osu.Game.Online.Rooms
@@ -14,14 +15,14 @@ namespace osu.Game.Online.Rooms
         private readonly long scoreId;
         private readonly long roomId;
         private readonly long playlistItemId;
-        private readonly ScoreInfo scoreInfo;
+        private readonly SubmittableScore score;
 
         public SubmitRoomScoreRequest(long scoreId, long roomId, long playlistItemId, ScoreInfo scoreInfo)
         {
             this.scoreId = scoreId;
             this.roomId = roomId;
             this.playlistItemId = playlistItemId;
-            this.scoreInfo = scoreInfo;
+            score = new SubmittableScore(scoreInfo);
         }
 
         protected override WebRequest CreateWebRequest()
@@ -31,7 +32,7 @@ namespace osu.Game.Online.Rooms
             req.ContentType = "application/json";
             req.Method = HttpMethod.Put;
 
-            req.AddRaw(JsonConvert.SerializeObject(scoreInfo, new JsonSerializerSettings
+            req.AddRaw(JsonConvert.SerializeObject(score, new JsonSerializerSettings
             {
                 ReferenceLoopHandling = ReferenceLoopHandling.Ignore
             }));

osu.Game/Overlays/BeatmapListing/Panels/BeatmapPanelDownloadButton.cs

@@ -86,7 +86,7 @@ namespace osu.Game.Overlays.BeatmapListing.Panels
                         break;
 
                     default:
-                        beatmaps.Download(new BeatmapSetInfo { OnlineBeatmapSetID = beatmapSet.OnlineID }, noVideoSetting.Value);
+                        beatmaps.Download(beatmapSet, noVideoSetting.Value);
                         break;
                 }
             };

osu.Game/Overlays/BeatmapSet/Buttons/HeaderDownloadButton.cs

@@ -108,7 +108,7 @@ namespace osu.Game.Overlays.BeatmapSet.Buttons
                     return;
                 }
 
-                beatmaps.Download(new BeatmapSetInfo { OnlineBeatmapSetID = beatmapSet.OnlineID }, noVideo);
+                beatmaps.Download(beatmapSet, noVideo);
             };
 
             localUser.BindTo(api.LocalUser);

osu.Game/Overlays/Profile/Sections/Ranks/DrawableProfileScore.cs

@@ -91,7 +91,7 @@ namespace osu.Game.Overlays.Profile.Sections.Ranks
                                                 {
                                                     new OsuSpriteText
                                                     {
-                                                        Text = $"{Score.Beatmap.DifficultyName}",
+                                                        Text = $"{Score.Beatmap?.DifficultyName}",
                                                         Font = OsuFont.GetFont(size: 12, weight: FontWeight.Regular),
                                                         Colour = colours.Yellow
                                                     },

osu.Game/Rulesets/Difficulty/DifficultyCalculator.cs

@@ -58,6 +58,11 @@ namespace osu.Game.Rulesets.Difficulty
             return CreateDifficultyAttributes(Beatmap, playableMods, skills, clockRate);
         }
 
+        /// <summary>
+        /// Calculates the difficulty of the beatmap and returns a set of <see cref="TimedDifficultyAttributes"/> representing the difficulty at every relevant time value in the beatmap.
+        /// </summary>
+        /// <param name="mods">The mods that should be applied to the beatmap.</param>
+        /// <returns>The set of <see cref="TimedDifficultyAttributes"/>.</returns>
         public List<TimedDifficultyAttributes> CalculateTimed(params Mod[] mods)
         {
             preProcess(mods);
@@ -77,7 +82,7 @@ namespace osu.Game.Rulesets.Difficulty
                 foreach (var skill in skills)
                     skill.ProcessInternal(hitObject);
 
-                attribs.Add(new TimedDifficultyAttributes(hitObject.EndTime, CreateDifficultyAttributes(progressiveBeatmap, playableMods, skills, clockRate)));
+                attribs.Add(new TimedDifficultyAttributes(hitObject.EndTime * clockRate, CreateDifficultyAttributes(progressiveBeatmap, playableMods, skills, clockRate)));
             }
 
             return attribs;

osu.Game/Rulesets/Difficulty/TimedDifficultyAttributes.cs

@@ -11,9 +11,21 @@ namespace osu.Game.Rulesets.Difficulty
     /// </summary>
     public class TimedDifficultyAttributes : IComparable<TimedDifficultyAttributes>
     {
+        /// <summary>
+        /// The non-clock-adjusted time value at which the attributes take effect.
+        /// </summary>
         public readonly double Time;
+
+        /// <summary>
+        /// The attributes.
+        /// </summary>
         public readonly DifficultyAttributes Attributes;
 
+        /// <summary>
+        /// Creates new <see cref="TimedDifficultyAttributes"/>.
+        /// </summary>
+        /// <param name="time">The non-clock-adjusted time value at which the attributes take effect.</param>
+        /// <param name="attributes">The attributes.</param>
         public TimedDifficultyAttributes(double time, DifficultyAttributes attributes)
         {
             Time = time;

osu.Game/Screens/OnlinePlay/DrawableRoomPlaylistItem.cs

@@ -105,7 +105,7 @@ namespace osu.Game.Screens.OnlinePlay
 
         private void refresh()
         {
-            difficultyIconContainer.Child = new DifficultyIcon(beatmap.Value, ruleset.Value, requiredMods) { Size = new Vector2(32) };
+            difficultyIconContainer.Child = new DifficultyIcon(beatmap.Value, ruleset.Value, requiredMods, performBackgroundDifficultyLookup: false) { Size = new Vector2(32) };
 
             beatmapText.Clear();
             beatmapText.AddLink(Item.Beatmap.Value.GetDisplayTitleRomanisable(), LinkAction.OpenBeatmap, Item.Beatmap.Value.OnlineBeatmapID.ToString(), null, text =>

osu.Game/Skinning/SkinManager.cs

@@ -194,68 +194,61 @@ namespace osu.Game.Skinning
             string nameLine = @$"Name: {item.Name}";
             string authorLine = @$"Author: {item.Creator}";
 
+            string[] newLines =
+            {
+                @"// The following content was automatically added by osu! during import, based on filename / folder metadata.",
+                @"[General]",
+                nameLine,
+                authorLine,
+            };
+
             var existingFile = item.Files.SingleOrDefault(f => f.Filename.Equals(@"skin.ini", StringComparison.OrdinalIgnoreCase));
 
-            if (existingFile != null)
+            if (existingFile == null)
             {
-                List<string> outputLines = new List<string>();
+                // In the case a skin doesn't have a skin.ini yet, let's create one.
+                writeNewSkinIni();
+                return;
+            }
 
-                bool addedName = false;
+            using (Stream stream = new MemoryStream())
-                bool addedAuthor = false;
+            {
-
+                using (var sw = new StreamWriter(stream, Encoding.UTF8, 1024, true))
-                using (var stream = Files.Storage.GetStream(existingFile.FileInfo.StoragePath))
-                using (var sr = new StreamReader(stream))
                 {
-                    string line;
+                    using (var existingStream = Files.Storage.GetStream(existingFile.FileInfo.StoragePath))
-
+                    using (var sr = new StreamReader(existingStream))
-                    while ((line = sr.ReadLine()) != null)
                     {
-                        if (line.StartsWith(@"Name:", StringComparison.Ordinal))
+                        string line;
-                        {
+                        while ((line = sr.ReadLine()) != null)
-                            outputLines.Add(nameLine);
-                            addedName = true;
-                        }
-                        else if (line.StartsWith(@"Author:", StringComparison.Ordinal))
-                        {
-                            outputLines.Add(authorLine);
-                            addedAuthor = true;
-                        }
-                        else
-                            outputLines.Add(line);
-                    }
-                }
-
-                if (!addedName || !addedAuthor)
-                {
-                    outputLines.AddRange(new[]
-                    {
-                        @"[General]",
-                        nameLine,
-                        authorLine,
-                    });
-                }
-
-                using (Stream stream = new MemoryStream())
-                {
-                    using (var sw = new StreamWriter(stream, Encoding.UTF8, 1024, true))
-                    {
-                        foreach (string line in outputLines)
                             sw.WriteLine(line);
                     }
 
-                    ReplaceFile(item, existingFile, stream);
+                    sw.WriteLine();
+
+                    foreach (string line in newLines)
+                        sw.WriteLine(line);
+                }
+
+                ReplaceFile(item, existingFile, stream);
+
+                // can be removed 20220502.
+                if (!ensureIniWasUpdated(item))
+                {
+                    Logger.Log($"Skin {item}'s skin.ini had issues and has been removed. Please report this and provide the problematic skin.", LoggingTarget.Database, LogLevel.Important);
+
+                    DeleteFile(item, item.Files.SingleOrDefault(f => f.Filename.Equals(@"skin.ini", StringComparison.OrdinalIgnoreCase)));
+                    writeNewSkinIni();
                 }
             }
-            else
+
+            void writeNewSkinIni()
             {
                 using (Stream stream = new MemoryStream())
                 {
                     using (var sw = new StreamWriter(stream, Encoding.UTF8, 1024, true))
                     {
-                        sw.WriteLine(@"[General]");
+                        foreach (string line in newLines)
-                        sw.WriteLine(nameLine);
+                            sw.WriteLine(line);
-                        sw.WriteLine(authorLine);
-                        sw.WriteLine(@"Version: latest");
                     }
 
                     AddFile(item, stream, @"skin.ini");
@@ -263,6 +256,17 @@ namespace osu.Game.Skinning
             }
         }
 
+        private bool ensureIniWasUpdated(SkinInfo item)
+        {
+            // This is a final consistency check to ensure that hash computation doesn't enter an infinite loop.
+            // With other changes to the surrounding code this should never be hit, but until we are 101% sure that there
+            // are no other cases let's avoid a hard startup crash by bailing and alerting.
+
+            var instance = GetSkin(item);
+
+            return instance.Configuration.SkinInfo.Name == item.Name;
+        }
+
         protected override Task Populate(SkinInfo model, ArchiveReader archive, CancellationToken cancellationToken = default)
         {
             var instance = GetSkin(model);

osu.Game/Tests/Visual/Multiplayer/TestMultiplayerClient.cs

@@ -62,7 +62,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
             return roomUser;
         }
 
-        public void AddNullUser() => addUser(new MultiplayerRoomUser(TestUserLookupCache.NULL_USER_ID));
+        public void TestAddUnresolvedUser() => addUser(new MultiplayerRoomUser(TestUserLookupCache.UNRESOLVED_USER_ID));
 
         private void addUser(MultiplayerRoomUser user)
         {

osu.Game/Tests/Visual/TestUserLookupCache.cs

@@ -14,11 +14,11 @@ namespace osu.Game.Tests.Visual
         /// A special user ID which <see cref="ComputeValueAsync"/> would return a <see langword="null"/> <see cref="User"/> for.
         /// As a simulation to what a regular <see cref="UserLookupCache"/> would return in the case of failing to fetch the user.
         /// </summary>
-        public const int NULL_USER_ID = -1;
+        public const int UNRESOLVED_USER_ID = -1;
 
         protected override Task<User> ComputeValueAsync(int lookup, CancellationToken token = default)
         {
-            if (lookup == NULL_USER_ID)
+            if (lookup == UNRESOLVED_USER_ID)
                 return Task.FromResult((User)null);
 
             return Task.FromResult(new User

osu.Game/osu.Game.csproj

@@ -23,9 +23,9 @@
     <PackageReference Include="HtmlAgilityPack" Version="1.11.37" />
     <PackageReference Include="Humanizer" Version="2.11.10" />
     <PackageReference Include="MessagePack" Version="2.3.85" />
-    <PackageReference Include="Microsoft.AspNetCore.SignalR.Client" Version="5.0.10" />
+    <PackageReference Include="Microsoft.AspNetCore.SignalR.Client" Version="5.0.11" />
-    <PackageReference Include="Microsoft.AspNetCore.SignalR.Protocols.MessagePack" Version="5.0.10" />
+    <PackageReference Include="Microsoft.AspNetCore.SignalR.Protocols.MessagePack" Version="5.0.11" />
-    <PackageReference Include="Microsoft.AspNetCore.SignalR.Protocols.NewtonsoftJson" Version="5.0.10" />
+    <PackageReference Include="Microsoft.AspNetCore.SignalR.Protocols.NewtonsoftJson" Version="5.0.11" />
     <PackageReference Include="Microsoft.EntityFrameworkCore.Sqlite" Version="2.2.6" />
     <PackageReference Include="Microsoft.EntityFrameworkCore.Sqlite.Core" Version="2.2.6" />
     <PackageReference Include="Microsoft.Extensions.Configuration.Abstractions" Version="5.0.0" />
@@ -38,8 +38,8 @@
     <PackageReference Include="Realm" Version="10.6.0" />
     <PackageReference Include="ppy.osu.Framework" Version="2021.1029.0" />
     <PackageReference Include="ppy.osu.Game.Resources" Version="2021.1026.0" />
-    <PackageReference Include="Sentry" Version="3.9.4" />
+    <PackageReference Include="Sentry" Version="3.10.0" />
-    <PackageReference Include="SharpCompress" Version="0.29.0" />
+    <PackageReference Include="SharpCompress" Version="0.30.0" />
     <PackageReference Include="NUnit" Version="3.13.2" />
     <PackageReference Include="System.ComponentModel.Annotations" Version="5.0.0" />
     <PackageReference Include="TagLibSharp" Version="2.2.0" />

osu.iOS.props

@@ -94,7 +94,7 @@
     <PackageReference Include="Microsoft.EntityFrameworkCore.Sqlite.Core" Version="2.2.6" />
     <PackageReference Include="Newtonsoft.Json" Version="13.0.1" />
     <PackageReference Include="ppy.osu.Framework" Version="2021.1029.0" />
-    <PackageReference Include="SharpCompress" Version="0.28.3" />
+    <PackageReference Include="SharpCompress" Version="0.30.0" />
     <PackageReference Include="NUnit" Version="3.13.2" />
     <PackageReference Include="SharpRaven" Version="2.4.0" />
     <PackageReference Include="System.ComponentModel.Annotations" Version="5.0.0" />