From 14ff4f03e132ab110fa14842ee1167a1f2f74722 Mon Sep 17 00:00:00 2001
From: pinzart <tiberiu.pinzariu@autodesk.com>
Date: Thu, 4 Aug 2022 11:29:41 -0400
Subject: [PATCH] fix edge case of ShowExecutionPreview

---
 .../ViewModels/Core/ConnectorViewModel.cs     |  2 +-
 src/Engine/ProtoScript/Runners/LiveRunner.cs  | 47 ++++++++++++++-----
 2 files changed, 35 insertions(+), 14 deletions(-)

diff --git a/src/DynamoCoreWpf/ViewModels/Core/ConnectorViewModel.cs b/src/DynamoCoreWpf/ViewModels/Core/ConnectorViewModel.cs
index de81aebf28f..6888f707cca 100644
--- a/src/DynamoCoreWpf/ViewModels/Core/ConnectorViewModel.cs
+++ b/src/DynamoCoreWpf/ViewModels/Core/ConnectorViewModel.cs
@@ -504,7 +504,7 @@ public PreviewState PreviewState
                     return PreviewState.None;
                 }
 
-                if (Nodevm.ShowExecutionPreview)
+                if (Nodevm.ShowExecutionPreview || NodeEnd.ShowExecutionPreview)
                 {
                     return PreviewState.ExecutionPreview;
                 }
diff --git a/src/Engine/ProtoScript/Runners/LiveRunner.cs b/src/Engine/ProtoScript/Runners/LiveRunner.cs
index cf5f5b8d8e7..6bf0245da7a 100644
--- a/src/Engine/ProtoScript/Runners/LiveRunner.cs
+++ b/src/Engine/ProtoScript/Runners/LiveRunner.cs
@@ -478,17 +478,20 @@ public ChangeSetComputer Clone()
             {
                 comp.currentSubTreeList.Add(subTreePairs.Key, subTreePairs.Value); 
             }
-
-            comp.csData = new ChangeSetData();
-            comp.csData.ContainsDeltaAST = csData.ContainsDeltaAST;
-            comp.csData.DeletedBinaryExprASTNodes = new List<AssociativeNode>(csData.DeletedBinaryExprASTNodes);
-            comp.csData.DeletedFunctionDefASTNodes = new List<AssociativeNode>(csData.DeletedFunctionDefASTNodes);
-            comp.csData.RemovedBinaryNodesFromModification = new List<AssociativeNode>(csData.RemovedBinaryNodesFromModification);
-            comp.csData.ModifiedNodesForRuntimeSetValue = new List<AssociativeNode>(csData.ModifiedNodesForRuntimeSetValue);
-            comp.csData.RemovedFunctionDefNodesFromModification = new List<AssociativeNode>(csData.RemovedFunctionDefNodesFromModification);
-            comp.csData.ForceExecuteASTList = new List<AssociativeNode>(csData.ForceExecuteASTList);
-            comp.csData.ModifiedFunctions = new List<AssociativeNode>(csData.ModifiedFunctions);
-            comp.csData.ModifiedNestedLangBlock = new List<AssociativeNode>(csData.ModifiedNestedLangBlock);
+            
+            if (csData != null)
+            {
+                comp.csData = new ChangeSetData();
+                comp.csData.ContainsDeltaAST = csData.ContainsDeltaAST;
+                comp.csData.DeletedBinaryExprASTNodes = new List<AssociativeNode>(csData.DeletedBinaryExprASTNodes);
+                comp.csData.DeletedFunctionDefASTNodes = new List<AssociativeNode>(csData.DeletedFunctionDefASTNodes);
+                comp.csData.RemovedBinaryNodesFromModification = new List<AssociativeNode>(csData.RemovedBinaryNodesFromModification);
+                comp.csData.ModifiedNodesForRuntimeSetValue = new List<AssociativeNode>(csData.ModifiedNodesForRuntimeSetValue);
+                comp.csData.RemovedFunctionDefNodesFromModification = new List<AssociativeNode>(csData.RemovedFunctionDefNodesFromModification);
+                comp.csData.ForceExecuteASTList = new List<AssociativeNode>(csData.ForceExecuteASTList);
+                comp.csData.ModifiedFunctions = new List<AssociativeNode>(csData.ModifiedFunctions);
+                comp.csData.ModifiedNestedLangBlock = new List<AssociativeNode>(csData.ModifiedNestedLangBlock);
+            }
             return comp;
         }
 
@@ -601,7 +604,7 @@ private IEnumerable<AssociativeNode> GetDeltaAstListDeleted(IEnumerable<Subtree>
             return deltaAstList;
         }
 
-        private IEnumerable<AssociativeNode> GetDeltaAstListAdded(IEnumerable<Subtree> addedSubTrees)
+        internal IEnumerable<AssociativeNode> GetDeltaAstListAdded(IEnumerable<Subtree> addedSubTrees)
         {
             var deltaAstList = new List<AssociativeNode>();            
             if (addedSubTrees != null)
@@ -787,7 +790,6 @@ private void UpdateCachedASTList(Subtree st, List<AssociativeNode> modifiedASTLi
             }
         }
 
-
         private IEnumerable<AssociativeNode> GetDeltaAstListModified(List<Subtree> modifiedSubTrees)
         {
             var deltaAstList = new List<AssociativeNode>();
@@ -1660,11 +1662,30 @@ private void CompileAndExecuteForDeltaExecution(List<AssociativeNode> astList)
         private List<Guid> PreviewInternal(GraphSyncData syncData)
         {
             var previewChangeSetComputer = changeSetComputer.Clone();
+
             // Get the list of ASTs that will be affected by syncData
             var previewAstList = previewChangeSetComputer.GetDeltaASTList(syncData);
 
             // Get the list of guid's affected by the astlist
             List<Guid> cbnGuidList = previewChangeSetComputer.EstimateNodesAffectedByASTList(previewAstList);
+
+            var finalDeltaAstList = new List<AssociativeNode>();
+
+            // Newly added nodes will not be in the VM yet.
+            // So we need to add them to the preview list.
+            var addCSComputer = changeSetComputer.Clone();
+
+            var addedDeltaAsts = addCSComputer.GetDeltaAstListAdded(syncData.AddedSubtrees);
+            foreach (AssociativeNode ast in addedDeltaAsts)
+            {
+                if (ast is BinaryExpressionNode bnode)
+                {
+                    if (!cbnGuidList.Contains(bnode.guid))
+                    {
+                        cbnGuidList.Add(bnode.guid);
+                    }
+                }
+            }
             return cbnGuidList;
         }