From f5000e9f3caae4fffcf587dccf1e6ca0c088896f Mon Sep 17 00:00:00 2001
From: Miro Brodlova <miro.brodlova@unity3d.com>
Date: Thu, 27 Nov 2025 12:48:01 +0100
Subject: [PATCH] Replace BinaryFormatter with DataContractSerializer

BinaryFormatter is deprecated in future .NET versions and may prevent
assemblies from unloading or return incorrect results.

Replaced with System.Runtime.Serialization.DataContractSerializer as
recommended for compatibility.

Changes:
- KdTree.cs: Replaced BinaryFormatter with DataContractSerializer in
  SaveToFile and LoadFromFile methods
- KdTreeNode.cs: Added DataContract and DataMember attributes
- Added [DataContract] and [DataMember] attributes to all serialized classes

Related to SCP-1555
---
 External/KdTree/KdTreeLib/KdTree.cs     | 18 ++++++++++++------
 External/KdTree/KdTreeLib/KdTreeNode.cs |  7 +++++++
 2 files changed, 19 insertions(+), 6 deletions(-)

diff --git a/External/KdTree/KdTreeLib/KdTree.cs b/External/KdTree/KdTreeLib/KdTree.cs
index 96cf75ea6..32c7d79b6 100644
--- a/External/KdTree/KdTreeLib/KdTree.cs
+++ b/External/KdTree/KdTreeLib/KdTree.cs
@@ -3,7 +3,7 @@
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
-using System.Runtime.Serialization.Formatters.Binary;
+using System.Runtime.Serialization;
 using System.Text;
 
 namespace UnityEngine.ProBuilder.KdTree
@@ -25,6 +25,7 @@ public DuplicateNodeError()
 	}
 
 	[Serializable]
+	[DataContract]
 	class KdTree<TKey, TValue> : IKdTree<TKey, TValue>
 	{
 		public KdTree(int dimensions, ITypeMath<TKey> typeMath)
@@ -40,12 +41,16 @@ public KdTree(int dimensions, ITypeMath<TKey> typeMath, AddDuplicateBehavior add
 			AddDuplicateBehavior = addDuplicateBehavior;
 		}
 
+		[DataMember]
 		private int dimensions;
 
+		[DataMember]
 		private ITypeMath<TKey> typeMath = null;
 
+		[DataMember]
 		private KdTreeNode<TKey, TValue> root = null;
 
+		[DataMember]
 		public AddDuplicateBehavior AddDuplicateBehavior { get; private set; }
 
 		public bool Add(TKey[] point, TValue value)
@@ -370,7 +375,8 @@ public KdTreeNode<TKey, TValue>[] RadialSearch(TKey[] center, TKey radius, int c
 			return neighbourArray;
 		}
 
-		public int Count { get; private set; }
+		[DataMember]
+	public int Count { get; private set; }
 
 		public bool TryFindValueAt(TKey[] point, out TValue value)
 		{
@@ -578,20 +584,20 @@ public void Clear()
 
 		public void SaveToFile(string filename)
 		{
-			BinaryFormatter formatter = new BinaryFormatter();
+			var serializer = new DataContractSerializer(typeof(KdTree<TKey, TValue>));
 			using (FileStream stream = File.Create(filename))
 			{
-				formatter.Serialize(stream, this);
+				serializer.WriteObject(stream, this);
 				stream.Flush();
 			}
 		}
 
 		public static KdTree<TKey, TValue> LoadFromFile(string filename)
 		{
-			BinaryFormatter formatter = new BinaryFormatter();
+			var serializer = new DataContractSerializer(typeof(KdTree<TKey, TValue>));
 			using (FileStream stream = File.Open(filename, FileMode.Open))
 			{
-				return (KdTree<TKey, TValue>)formatter.Deserialize(stream);
+				return (KdTree<TKey, TValue>)serializer.ReadObject(stream);
 			}
 
 		}
diff --git a/External/KdTree/KdTreeLib/KdTreeNode.cs b/External/KdTree/KdTreeLib/KdTreeNode.cs
index 41adac572..35672ddd7 100644
--- a/External/KdTree/KdTreeLib/KdTreeNode.cs
+++ b/External/KdTree/KdTreeLib/KdTreeNode.cs
@@ -2,10 +2,12 @@
 using System.Text;
 using System.Linq;
 using System.Collections.Generic;
+using System.Runtime.Serialization;
 
 namespace UnityEngine.ProBuilder.KdTree
 {
 	[Serializable]
+	[DataContract]
 	class KdTreeNode<TKey, TValue>
 	{
 		public KdTreeNode()
@@ -18,11 +20,16 @@ public KdTreeNode(TKey[] point, TValue value)
 			Value = value;
 		}
 
+		[DataMember]
 		public TKey[] Point;
+		[DataMember]
 		public TValue Value = default(TValue);
+		[DataMember]
 		public List<TValue> Duplicates = null;
 
+		[DataMember]
 		internal KdTreeNode<TKey, TValue> LeftChild = null;
+		[DataMember]
 		internal KdTreeNode<TKey, TValue> RightChild = null;
 
 		internal KdTreeNode<TKey, TValue> this[int compare]