From 96de1fdaa152dc854122b1e3aee98acbedfee463 Mon Sep 17 00:00:00 2001
From: Kamron Batman <3953314+kamronbatman@users.noreply.github.com>
Date: Sun, 7 Jul 2024 12:09:13 -0700
Subject: [PATCH] fix: Fixes NPE in PooledRefList sort (#1864)

---
 Projects/Server/Collections/PooledRefList.cs | 32 ++++++++------------
 1 file changed, 13 insertions(+), 19 deletions(-)

diff --git a/Projects/Server/Collections/PooledRefList.cs b/Projects/Server/Collections/PooledRefList.cs
index 27eba2be1..8aff2f7b3 100644
--- a/Projects/Server/Collections/PooledRefList.cs
+++ b/Projects/Server/Collections/PooledRefList.cs
@@ -6,6 +6,7 @@ using System.Buffers;
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
 using Server.Buffers;
 
 namespace Server.Collections;
@@ -946,13 +947,16 @@ public ref struct PooledRefList<T>
         _version++;
     }
 
-    // Sorts the elements in this list.  Uses the default comparer and
-    // Array.Sort.
-    public void Sort() => Sort(0, Count, null);
-
     // Sorts the elements in this list.  Uses Array.Sort with the
     // provided comparer.
-    public void Sort(IComparer<T>? comparer) => Sort(0, Count, comparer);
+    public void Sort(IComparer<T>? comparer = null)
+    {
+        if (_size > 1)
+        {
+            Array.Sort(_items, 0, _size, comparer);
+        }
+        _version++;
+    }
 
     // Sorts the elements in a section of this list. The sort compares the
     // elements to each other using the given IComparer interface. If
@@ -964,15 +968,8 @@ public ref struct PooledRefList<T>
     //
     public void Sort(int index, int count, IComparer<T>? comparer)
     {
-        if (index < 0)
-        {
-            throw new ArgumentOutOfRangeException(nameof(index));
-        }
-
-        if (count < 0)
-        {
-            throw new ArgumentOutOfRangeException(nameof(count));
-        }
+        ArgumentOutOfRangeException.ThrowIfNegative(index);
+        ArgumentOutOfRangeException.ThrowIfNegative(count);
 
         if (_size - index < count)
         {
@@ -988,14 +985,11 @@ public ref struct PooledRefList<T>
 
     public void Sort(Comparison<T> comparison)
     {
-        if (comparison == null)
-        {
-            throw new ArgumentNullException(nameof(comparison));
-        }
+        ArgumentNullException.ThrowIfNull(comparison);
 
         if (_size > 1)
         {
-            Array.Sort(_items, comparison);
+            _items.AsSpan(0, _size).Sort(comparison);
         }
         _version++;
     }