Prevent Unity crashing on PropertyInfo evaluation

Unity crashes from checking Canvas.renderingDisplaySize on a Canvas set to WorldSpace with no worldCamera set.

Author: sinai-dev

src/CacheObject/CacheMember.cs

@@ -21,7 +21,7 @@ public abstract class CacheMember : CacheObjectBase
     {
         public abstract Type DeclaringType { get; }
         public string NameForFiltering { get; protected set; }
-        public object DeclaringInstance => IsStatic ? null : (m_declaringInstance ?? (m_declaringInstance = Owner.Target.TryCast(DeclaringType)));
+        public object DeclaringInstance => IsStatic ? null : (m_declaringInstance ??= Owner.Target.TryCast(DeclaringType));
         private object m_declaringInstance;
 
         public abstract bool IsStatic { get; }
@@ -94,8 +94,8 @@ protected override void SetValueState(CacheObjectCell cell, ValueStateArgs args)
             base.SetValueState(cell, args);
         }
 
-        private static readonly Color evalEnabledColor = new Color(0.15f, 0.25f, 0.15f);
-        private static readonly Color evalDisabledColor = new Color(0.15f, 0.15f, 0.15f);
+        private static readonly Color evalEnabledColor = new(0.15f, 0.25f, 0.15f);
+        private static readonly Color evalDisabledColor = new(0.15f, 0.15f, 0.15f);
 
         protected override bool TryAutoEvaluateIfUnitialized(CacheObjectCell objectcell)
         {
@@ -242,7 +242,7 @@ private static void TryCacheMember(MemberInfo member, List<CacheMember> list, Ha
 
                 var sig = GetSig(member);
 
-                //ExplorerCore.Log($"Trying to cache member {sig}... ({member.MemberType})");
+                // ExplorerCore.Log($"Trying to cache member {sig}... ({member.MemberType})");
 
                 CacheMember cached;
                 Type returnType;

src/CacheObject/CacheProperty.cs

@@ -3,7 +3,9 @@
 using System.Linq;
 using System.Reflection;
 using System.Text;
+using UnityEngine;
 using UnityExplorer.Inspectors;
+using UnityExplorer.Runtime;
 
 namespace UnityExplorer.CacheObject
 {
@@ -28,6 +30,8 @@ protected override object TryEvaluate()
         {
             try
             {
+                UnityCrashPrevention.CheckPropertyInfoEvaluation(this);
+
                 object ret;
                 if (HasArguments)
                     ret = PropertyInfo.GetValue(DeclaringInstance, this.Evaluator.TryParseArguments());

src/Inspectors/InspectorManager.cs

@@ -18,7 +18,7 @@ namespace UnityExplorer
 {
     public static class InspectorManager
     {
-        public static readonly List<InspectorBase> Inspectors = new List<InspectorBase>();
+        public static readonly List<InspectorBase> Inspectors = new();
 
         public static InspectorBase ActiveInspector { get; private set; }
         private static InspectorBase lastActiveInspector;
@@ -94,17 +94,17 @@ internal static void CloseAllTabs()
         }
 
         private static void CreateInspector<T>(object target, bool staticReflection = false,
-            CacheObjectBase sourceCache = null) where T : InspectorBase
+            CacheObjectBase parentObject = null) where T : InspectorBase
         {
             var inspector = Pool<T>.Borrow();
             Inspectors.Add(inspector);
             inspector.Target = target;
 
-            if (sourceCache != null && sourceCache.CanWrite)
+            if (parentObject != null && parentObject.CanWrite)
             {
                 // only set parent cache object if we are inspecting a struct, otherwise there is no point.
                 if (target.GetType().IsValueType && inspector is ReflectionInspector ri)
-                    ri.ParentCacheObject = sourceCache;
+                    ri.ParentCacheObject = parentObject;
             }
 
             UIManager.SetPanelActive(UIManager.Panels.Inspector, true);

src/Runtime/UnityCrashPrevention.cs

@@ -0,0 +1,23 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using UnityEngine;
+using UnityExplorer.CacheObject;
+
+namespace UnityExplorer.Runtime
+{
+    public static class UnityCrashPrevention
+    {
+        public static void CheckPropertyInfoEvaluation(CacheProperty cacheProp)
+        {
+            if (cacheProp.PropertyInfo.Name == "renderingDisplaySize"
+                && cacheProp.Owner.Target is Canvas canvas
+                && canvas.renderMode == RenderMode.WorldSpace
+                && !canvas.worldCamera)
+            {
+                throw new Exception("Canvas is set to RenderMode.WorldSpace but has no worldCamera, cannot get value.");
+            }
+        }
+    }
+}

src/UnityExplorer.csproj

@@ -259,6 +259,7 @@
     <Compile Include="CacheObject\Views\CacheListEntryCell.cs" />
     <Compile Include="CacheObject\Views\CacheMemberCell.cs" />
     <Compile Include="CacheObject\Views\CacheObjectCell.cs" />
+    <Compile Include="Runtime\UnityCrashPrevention.cs" />
     <Compile Include="UI\DisplayManager.cs" />
     <Compile Include="UI\Notification.cs" />
     <Compile Include="UI\Panels\ClipboardPanel.cs" />