From bbe08be462ee66b8c55594d20360b0284eef66f4 Mon Sep 17 00:00:00 2001
From: Wojtek Figat <wojtek@figat.pl>
Date: Mon, 4 Mar 2024 18:25:57 +0100
Subject: [PATCH] Fix duplicating array values in Editor

#1959
---
 Source/Editor/CustomEditors/CustomEditor.cs    | 16 ++--------------
 .../CustomEditors/Editors/ArrayEditor.cs       |  4 ++--
 Source/Editor/Utilities/Utils.cs               | 18 +++++++++++++++++-
 3 files changed, 21 insertions(+), 17 deletions(-)

diff --git a/Source/Editor/CustomEditors/CustomEditor.cs b/Source/Editor/CustomEditors/CustomEditor.cs
index ab87389de..ef6302e8e 100644
--- a/Source/Editor/CustomEditors/CustomEditor.cs
+++ b/Source/Editor/CustomEditors/CustomEditor.cs
@@ -747,7 +747,7 @@ namespace FlaxEditor.CustomEditors
         /// </summary>
         public void SetValueToDefault()
         {
-            SetValueCloned(Values.DefaultValue);
+            SetValue(Utilities.Utils.CloneValue(Values.DefaultValue));
         }
 
         /// <summary>
@@ -784,19 +784,7 @@ namespace FlaxEditor.CustomEditors
                 return;
             }
 
-            SetValueCloned(Values.ReferenceValue);
-        }
-
-        private void SetValueCloned(object value)
-        {
-            // For objects (eg. arrays) we need to clone them to prevent editing default/reference value within editor
-            if (value != null && !value.GetType().IsValueType)
-            {
-                var json = JsonSerializer.Serialize(value);
-                value = JsonSerializer.Deserialize(json, value.GetType());
-            }
-
-            SetValue(value);
+            SetValue(Utilities.Utils.CloneValue(Values.ReferenceValue));
         }
 
         /// <summary>
diff --git a/Source/Editor/CustomEditors/Editors/ArrayEditor.cs b/Source/Editor/CustomEditors/Editors/ArrayEditor.cs
index 276417f96..25163febd 100644
--- a/Source/Editor/CustomEditors/Editors/ArrayEditor.cs
+++ b/Source/Editor/CustomEditors/Editors/ArrayEditor.cs
@@ -2,7 +2,6 @@
 
 using System;
 using System.Collections;
-using FlaxEditor.Scripting;
 using FlaxEngine;
 using FlaxEngine.Utilities;
 
@@ -47,8 +46,9 @@ namespace FlaxEditor.CustomEditors.Editors
                     if (elementType.IsValueType || NotNullItems)
                     {
                         // Fill new entries with the last value
+                        var lastValue = array.GetValue(oldSize - 1);
                         for (int i = oldSize; i < newSize; i++)
-                            Array.Copy(array, oldSize - 1, newValues, i, 1);
+                            newValues.SetValue(Utilities.Utils.CloneValue(lastValue), i);
                     }
                     else
                     {
diff --git a/Source/Editor/Utilities/Utils.cs b/Source/Editor/Utilities/Utils.cs
index 54518bf9e..7e2d9f628 100644
--- a/Source/Editor/Utilities/Utils.cs
+++ b/Source/Editor/Utilities/Utils.cs
@@ -11,7 +11,6 @@ using System.Globalization;
 using System.Collections.Generic;
 using System.IO;
 using System.Reflection;
-using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
 using System.Text;
 using System.Text.RegularExpressions;
@@ -20,6 +19,7 @@ using FlaxEditor.GUI.Input;
 using FlaxEditor.GUI.Tree;
 using FlaxEditor.SceneGraph;
 using FlaxEngine;
+using FlaxEngine.Json;
 using FlaxEngine.GUI;
 using FlaxEngine.Utilities;
 using FlaxEditor.Windows;
@@ -203,6 +203,22 @@ namespace FlaxEditor.Utilities
             }
         }
 
+        /// <summary>
+        /// Clones the value. handles non-value types (such as arrays) that need deep value cloning.
+        /// </summary>
+        /// <param name="value">The source value to clone.</param>
+        /// <returns>The duplicated value.</returns>
+        internal static object CloneValue(object value)
+        {
+            // For objects (eg. arrays) we need to clone them to prevent editing default/reference value within editor
+            if (value != null && (!value.GetType().IsValueType || !value.GetType().IsClass))
+            {
+                var json = JsonSerializer.Serialize(value);
+                value = JsonSerializer.Deserialize(json, value.GetType());
+            }
+            return value;
+        }
+
         /// <summary>
         /// The colors for the keyframes used by the curve editor.
         /// </summary>