From a5281739438f0c4bc38f52ce3a7f57cb980e0f98 Mon Sep 17 00:00:00 2001
From: Dean Herbert <pe@ppy.sh>
Date: Fri, 8 Sep 2017 19:04:24 +0900
Subject: [PATCH] Ensure that WorkingBeatmap's Beatmap is never null

Also ensures some extra fields inside Beatmap have non-null defaults.
---
 osu.Game/Beatmaps/Beatmap.cs                | 8 ++++----
 osu.Game/Beatmaps/DummyWorkingBeatmap.cs    | 6 +-----
 osu.Game/Beatmaps/Formats/BeatmapDecoder.cs | 4 +---
 osu.Game/Beatmaps/WorkingBeatmap.cs         | 2 +-
 4 files changed, 7 insertions(+), 13 deletions(-)

diff --git a/osu.Game/Beatmaps/Beatmap.cs b/osu.Game/Beatmaps/Beatmap.cs
index 82777734bb..15953fcd82 100644
--- a/osu.Game/Beatmaps/Beatmap.cs
+++ b/osu.Game/Beatmaps/Beatmap.cs
@@ -17,7 +17,7 @@ namespace osu.Game.Beatmaps
     public class Beatmap<T>
         where T : HitObject
     {
-        public BeatmapInfo BeatmapInfo;
+        public BeatmapInfo BeatmapInfo = new BeatmapInfo();
         public ControlPointInfo ControlPointInfo = new ControlPointInfo();
         public List<BreakPeriod> Breaks = new List<BreakPeriod>();
         public readonly List<Color4> ComboColors = new List<Color4>
@@ -33,7 +33,7 @@ namespace osu.Game.Beatmaps
         /// <summary>
         /// The HitObjects this Beatmap contains.
         /// </summary>
-        public List<T> HitObjects;
+        public List<T> HitObjects = new List<T>();
 
         /// <summary>
         /// Total amount of break time in the beatmap.
@@ -44,12 +44,13 @@ namespace osu.Game.Beatmaps
         /// Constructs a new beatmap.
         /// </summary>
         /// <param name="original">The original beatmap to use the parameters of.</param>
-        public Beatmap(Beatmap original = null)
+        public Beatmap(Beatmap<T> original = null)
         {
             BeatmapInfo = original?.BeatmapInfo.DeepClone() ?? BeatmapInfo;
             ControlPointInfo = original?.ControlPointInfo ?? ControlPointInfo;
             Breaks = original?.Breaks ?? Breaks;
             ComboColors = original?.ComboColors ?? ComboColors;
+            HitObjects = original?.HitObjects ?? HitObjects;
         }
     }
 
@@ -65,7 +66,6 @@ namespace osu.Game.Beatmaps
         public Beatmap(Beatmap original = null)
             : base(original)
         {
-            HitObjects = original?.HitObjects;
         }
     }
 }
diff --git a/osu.Game/Beatmaps/DummyWorkingBeatmap.cs b/osu.Game/Beatmaps/DummyWorkingBeatmap.cs
index 479f274efb..cc982c7a70 100644
--- a/osu.Game/Beatmaps/DummyWorkingBeatmap.cs
+++ b/osu.Game/Beatmaps/DummyWorkingBeatmap.cs
@@ -7,7 +7,6 @@ using osu.Framework.Audio.Track;
 using osu.Framework.Graphics.Textures;
 using osu.Game.Rulesets;
 using osu.Game.Rulesets.Mods;
-using osu.Game.Rulesets.Objects;
 using osu.Game.Rulesets.Scoring;
 using osu.Game.Rulesets.UI;
 
@@ -42,10 +41,7 @@ namespace osu.Game.Beatmaps
             this.game = game;
         }
 
-        protected override Beatmap GetBeatmap() => new Beatmap
-        {
-            HitObjects = new List<HitObject>(),
-        };
+        protected override Beatmap GetBeatmap() => new Beatmap();
 
         protected override Texture GetBackground() => game.Textures.Get(@"Backgrounds/bg4");
 
diff --git a/osu.Game/Beatmaps/Formats/BeatmapDecoder.cs b/osu.Game/Beatmaps/Formats/BeatmapDecoder.cs
index 234d65eee4..81695c3b5a 100644
--- a/osu.Game/Beatmaps/Formats/BeatmapDecoder.cs
+++ b/osu.Game/Beatmaps/Formats/BeatmapDecoder.cs
@@ -4,7 +4,6 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
-using osu.Game.Rulesets.Objects;
 
 namespace osu.Game.Beatmaps.Formats
 {
@@ -21,7 +20,7 @@ namespace osu.Game.Beatmaps.Formats
         {
             string line;
             do { line = stream.ReadLine()?.Trim(); }
-                while (line != null && line.Length == 0);
+            while (line != null && line.Length == 0);
 
             if (line == null || !decoders.ContainsKey(line))
                 throw new IOException(@"Unknown file format");
@@ -47,7 +46,6 @@ namespace osu.Game.Beatmaps.Formats
         {
             var beatmap = new Beatmap
             {
-                HitObjects = new List<HitObject>(),
                 BeatmapInfo = new BeatmapInfo
                 {
                     Metadata = new BeatmapMetadata(),
diff --git a/osu.Game/Beatmaps/WorkingBeatmap.cs b/osu.Game/Beatmaps/WorkingBeatmap.cs
index 462f94ed7c..4797f438d0 100644
--- a/osu.Game/Beatmaps/WorkingBeatmap.cs
+++ b/osu.Game/Beatmaps/WorkingBeatmap.cs
@@ -54,7 +54,7 @@ namespace osu.Game.Beatmaps
                 {
                     if (beatmap != null) return beatmap;
 
-                    beatmap = GetBeatmap();
+                    beatmap = GetBeatmap() ?? new Beatmap();
 
                     // use the database-backed info.
                     beatmap.BeatmapInfo = BeatmapInfo;