From 8c52b67752245cd9e2ed2ee06be7a5b28d0055c4 Mon Sep 17 00:00:00 2001
From: Michael Kirschner <mjk.kirschner@gmail.com>
Date: Tue, 25 Oct 2022 12:00:00 -0400
Subject: [PATCH] fix bug (#13423)

add test
---
 .../Workspaces/SerializationConverters.cs     |  7 ++-
 test/DynamoCoreTests/SerializationTests.cs    | 23 ++++++-
 test/core/serialization/nullWorkspaceRefs.dyn | 61 +++++++++++++++++++
 3 files changed, 89 insertions(+), 2 deletions(-)
 create mode 100644 test/core/serialization/nullWorkspaceRefs.dyn

diff --git a/src/DynamoCore/Graph/Workspaces/SerializationConverters.cs b/src/DynamoCore/Graph/Workspaces/SerializationConverters.cs
index 47fd8463887..8f82282bca5 100644
--- a/src/DynamoCore/Graph/Workspaces/SerializationConverters.cs
+++ b/src/DynamoCore/Graph/Workspaces/SerializationConverters.cs
@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.Linq;
@@ -604,6 +604,11 @@ public override object ReadJson(JsonReader reader, Type objectType, object exist
             if (obj[NodeLibraryDependenciesPropString] != null)
             {
                 workspaceReferences = obj[NodeLibraryDependenciesPropString].ToObject<IEnumerable<INodeLibraryDependencyInfo>>(serializer);
+                //if deserialization failed, reset to empty.
+                if (workspaceReferences == null)
+                {
+                    workspaceReferences = new List<INodeLibraryDependencyInfo>();
+                }
             }
             else
             {
diff --git a/test/DynamoCoreTests/SerializationTests.cs b/test/DynamoCoreTests/SerializationTests.cs
index c9ef74cf713..5758f6ad944 100644
--- a/test/DynamoCoreTests/SerializationTests.cs
+++ b/test/DynamoCoreTests/SerializationTests.cs
@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Globalization;
 using System.IO;
@@ -650,6 +650,27 @@ public void ConverterDoesNotThrowWithNullEngine()
             CurrentDynamoModel.AddHomeWorkspace();
             Assert.DoesNotThrow(() => { CurrentDynamoModel.CurrentWorkspace.ToJson(null); });
         }
+        [Test]
+        public void NullWorkspaceRefsDeserializedAsEmpty()
+        {
+
+            var testFile = Path.Combine(TestDirectory, @"core\serialization\nullWorkspaceRefs.dyn");
+            var json = File.ReadAllText(testFile);
+
+            Assert.DoesNotThrow(() =>
+            {
+               var ws =  WorkspaceModel.FromJson(
+                json, this.CurrentDynamoModel.LibraryServices,
+                null,
+                null,
+                this.CurrentDynamoModel.NodeFactory,
+                true,
+                true,
+                this.CurrentDynamoModel.CustomNodeManager);
+
+                Assert.NotNull(ws);
+            });
+        }
 
         [Test]
         public void ReadConverterDoesNotThrowWithNullEngineAndScheduler()
diff --git a/test/core/serialization/nullWorkspaceRefs.dyn b/test/core/serialization/nullWorkspaceRefs.dyn
new file mode 100644
index 00000000000..14c1baebf73
--- /dev/null
+++ b/test/core/serialization/nullWorkspaceRefs.dyn
@@ -0,0 +1,61 @@
+{
+  "Uuid": "077eb433-543f-4cc7-bc2a-91fcaea5687e",
+  "IsCustomNode": false,
+  "Description": "",
+  "Name": "broken",
+  "ElementResolver": {
+    "ResolutionMap": {}
+  },
+  "Inputs": [],
+  "Outputs": [],
+  "Nodes": [],
+  "Connectors": [],
+  "Dependencies": [],
+  "NodeLibraryDependencies": null,
+  "Thumbnail": "",
+  "GraphDocumentationURL": null,
+  "ExtensionWorkspaceData": [
+    {
+      "ExtensionGuid": "28992e1d-abb9-417f-8b1b-05e053bee670",
+      "Name": "Properties",
+      "Version": "2.16",
+      "Data": {}
+    }
+  ],
+  "Author": "",
+  "Linting": {
+    "activeLinter": "None",
+    "activeLinterId": "7b75fb44-43fd-4631-a878-29f4d5d8399a",
+    "warningCount": 0,
+    "errorCount": 0
+  },
+  "Bindings": [],
+  "View": {
+    "Dynamo": {
+      "ScaleFactor": 1.0,
+      "HasRunWithoutCrash": true,
+      "IsVisibleInDynamoLibrary": true,
+      "Version": "2.16.0.1926",
+      "RunType": "Automatic",
+      "RunPeriod": "1000"
+    },
+    "Camera": {
+      "Name": "Background Preview",
+      "EyeX": -17.0,
+      "EyeY": 24.0,
+      "EyeZ": 50.0,
+      "LookX": 12.0,
+      "LookY": -13.0,
+      "LookZ": -58.0,
+      "UpX": 0.0,
+      "UpY": 1.0,
+      "UpZ": 0.0
+    },
+    "ConnectorPins": [],
+    "NodeViews": [],
+    "Annotations": [],
+    "X": 0.0,
+    "Y": 0.0,
+    "Zoom": 1.0
+  }
+}
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