From 780d1c40b9b80f965197572f2b7aca459cdf2073 Mon Sep 17 00:00:00 2001
From: David Morasz <david.morasz@meso.design>
Date: Sun, 11 Aug 2019 22:32:28 +0200
Subject: [PATCH] added some null safety

---
 AttachedValuesNodes.cs | 6 +++++-
 ElementInfoNode.cs     | 1 +
 SubContextNodes.cs     | 3 ++-
 3 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/AttachedValuesNodes.cs b/AttachedValuesNodes.cs
index 7c3ee6d..0295bb3 100644
--- a/AttachedValuesNodes.cs
+++ b/AttachedValuesNodes.cs
@@ -28,6 +28,7 @@ public void Evaluate(int SpreadMax)
             for (int i = 0; i < FElement.SliceCount; i++)
             {
                 var element = FElement[i];
+                if (element == null) continue;
                 if (element.Value == null)
                 {
                     FVals[i].SliceCount = FTexts[i].SliceCount = FAuxKeys[i].SliceCount = FAuxVals[i].SliceCount = 0;
@@ -72,6 +73,7 @@ public void Evaluate(int SpreadMax)
             for (int i = 0; i < FElement.SliceCount; i++)
             {
                 var element = FElement[i];
+                if (element == null) continue;
                 if (element.Value == null)
                 {
                     element.Value = new AttachedValues();
@@ -114,6 +116,7 @@ public void Evaluate(int SpreadMax)
             for (int i = 0; i < FElement.SliceCount; i++)
             {
                 var element = FElement[i];
+                if(element == null) continue;
                 if (element.Value == null)
                 {
                     element.Value = new AttachedValues();
@@ -181,7 +184,8 @@ public void Evaluate(int SpreadMax)
             
             for (int i = 0; i < FElement.SliceCount; i++)
             {
-                if(FElement[i].Value != null)
+                if (FElement[i] == null) continue;
+                if (FElement[i].Value != null)
                 {
                     if(FElement[i].Value.Auxiliary.Count > 0)
                     {
diff --git a/ElementInfoNode.cs b/ElementInfoNode.cs
index 5e05066..f03a793 100644
--- a/ElementInfoNode.cs
+++ b/ElementInfoNode.cs
@@ -210,6 +210,7 @@ public class GuiElementInfoNode : IPluginEvaluate
 
         protected void AssignElementOutputs(NotuiElement element, int i)
         {
+            if (element == null) return;
             if (element.EnvironmentObject is VEnvironmentData venvdat)
             {
                 TouchesOut[i] = venvdat.Touches;
diff --git a/SubContextNodes.cs b/SubContextNodes.cs
index 6f71952..02b9e78 100644
--- a/SubContextNodes.cs
+++ b/SubContextNodes.cs
@@ -140,10 +140,11 @@ public void Evaluate(int SpreadMax)
                     for (int j = 0; j < FElements[i].SliceCount; j++)
                     {
                         if (FElements[i][j] == null) continue;
-                        if (_prevElements[i].Contains(FElements[i][j])) continue;
+                        if (_prevElements[i]?.Contains(FElements[i][j]) ?? true) continue;
                         FElements[i][j].IsChanged = ElementNodeUtils.ChangedFrames;
                     }
 
+                    if(_prevElements[i] == null) _prevElements[i] = new Spread<ElementPrototype>();
                     _prevElements[i].AssignFrom(FElements[i]);
 
                     if (_areElementsChanged > 0 && FAutoUpdateElements[i] || FUpdateElements[i])