From 888782c1aca4d8394ec4f49dc8372599dcded1c0 Mon Sep 17 00:00:00 2001
From: glopesdev <glopesdev@users.noreply.github.com>
Date: Tue, 27 Sep 2022 13:15:10 +0100
Subject: [PATCH] Ensure nested mashup sources are always serialized

---
 Bonsai.Editor/Layout/LayoutHelper.cs | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/Bonsai.Editor/Layout/LayoutHelper.cs b/Bonsai.Editor/Layout/LayoutHelper.cs
index 647f718a2..1f205ae66 100644
--- a/Bonsai.Editor/Layout/LayoutHelper.cs
+++ b/Bonsai.Editor/Layout/LayoutHelper.cs
@@ -273,16 +273,13 @@ static void SerializeMashupVisualizerSettings(
             foreach (var source in mashupVisualizer.MashupSources)
             {
                 var sourceIndex = GetMashupSourceIndex(source, topologicalOrder);
-                if (sourceIndex.HasValue)
-                {
-                    var mashupSource = SerializeMashupSource(sourceIndex.Value, source.Visualizer, topologicalOrder);
-                    root.Add(mashupSource);
-                }
+                var mashupSource = SerializeMashupSource(sourceIndex, source.Visualizer, topologicalOrder);
+                root.Add(mashupSource);
             }
         }
 
         static XElement SerializeMashupSource(
-            int sourceIndex,
+            int? sourceIndex,
             DialogTypeVisualizer visualizer,
             IEnumerable<Node<ExpressionBuilder, ExpressionBuilderArgument>> topologicalOrder)
         {
@@ -301,7 +298,7 @@ static XElement SerializeMashupSource(
 
             visualizerSettings = new XDocument(
                 new XElement(MashupSettingsElement,
-                new XElement(MashupSourceElement, sourceIndex),
+                sourceIndex.HasValue ? new XElement(MashupSourceElement, sourceIndex.Value) : null,
                 new XElement(nameof(VisualizerDialogSettings.VisualizerTypeName), visualizerType.FullName),
                 new XElement(nameof(VisualizerDialogSettings.VisualizerSettings), visualizerSettings.Root)));
             return visualizerSettings.Root;