From 60a010efd1f5a92d8033a4474583e35ab0459894 Mon Sep 17 00:00:00 2001
From: biwa <6475593+biwa@users.noreply.github.com>
Date: Fri, 9 Oct 2020 18:53:10 +0200
Subject: [PATCH] Editing modes: fixed some crashes related to undoing/redoing
 while objects with associations were highlighted

---
 Source/Plugins/BuilderModes/ClassicModes/LinedefsMode.cs | 8 ++++++++
 Source/Plugins/BuilderModes/ClassicModes/SectorsMode.cs  | 8 ++++++++
 Source/Plugins/BuilderModes/ClassicModes/ThingsMode.cs   | 8 ++++++++
 3 files changed, 24 insertions(+)

diff --git a/Source/Plugins/BuilderModes/ClassicModes/LinedefsMode.cs b/Source/Plugins/BuilderModes/ClassicModes/LinedefsMode.cs
index 2e7c04f..8bdbde6 100644
--- a/Source/Plugins/BuilderModes/ClassicModes/LinedefsMode.cs
+++ b/Source/Plugins/BuilderModes/ClassicModes/LinedefsMode.cs
@@ -938,6 +938,10 @@ namespace CodeImp.DoomBuilder.BuilderModes
 				General.Map.Map.ConvertSelection(SelectionType.Linedefs);
 			}
 
+			// If something is highlighted make sure to update the association so that it contains valid data
+			if (highlighted != null && !highlighted.IsDisposed)
+				highlightasso.Set(highlighted);
+
 			// Update selection info and labels
 			UpdateSelectionInfo();
 			SetupSectorLabels();
@@ -955,6 +959,10 @@ namespace CodeImp.DoomBuilder.BuilderModes
 				General.Map.Map.ConvertSelection(SelectionType.Linedefs);
 			}
 
+			// If something is highlighted make sure to update the association so that it contains valid data
+			if (highlighted != null && !highlighted.IsDisposed)
+				highlightasso.Set(highlighted);
+
 			// Update selection info and labels
 			UpdateSelectionInfo();
 			SetupSectorLabels();
diff --git a/Source/Plugins/BuilderModes/ClassicModes/SectorsMode.cs b/Source/Plugins/BuilderModes/ClassicModes/SectorsMode.cs
index fedaada..8c39c87 100644
--- a/Source/Plugins/BuilderModes/ClassicModes/SectorsMode.cs
+++ b/Source/Plugins/BuilderModes/ClassicModes/SectorsMode.cs
@@ -1502,6 +1502,10 @@ namespace CodeImp.DoomBuilder.BuilderModes
 				General.Map.Map.ConvertSelection(SelectionType.Sectors);
 			}
 
+			// If something is highlighted make sure to update the association so that it contains valid data
+			if (highlighted != null && !highlighted.IsDisposed)
+				highlightasso.Set(highlighted);
+
 			// Clear labels
 			SetupLabels();
 			UpdateEffectLabels(); //mxd
@@ -1531,6 +1535,10 @@ namespace CodeImp.DoomBuilder.BuilderModes
 				General.Map.Map.ConvertSelection(SelectionType.Sectors);
 			}
 
+			// If something is highlighted make sure to update the association so that it contains valid data
+			if (highlighted != null && !highlighted.IsDisposed)
+				highlightasso.Set(highlighted);
+
 			// Clear labels
 			SetupLabels();
 			UpdateEffectLabels(); //mxd
diff --git a/Source/Plugins/BuilderModes/ClassicModes/ThingsMode.cs b/Source/Plugins/BuilderModes/ClassicModes/ThingsMode.cs
index ec82487..66fc73b 100644
--- a/Source/Plugins/BuilderModes/ClassicModes/ThingsMode.cs
+++ b/Source/Plugins/BuilderModes/ClassicModes/ThingsMode.cs
@@ -570,6 +570,10 @@ namespace CodeImp.DoomBuilder.BuilderModes
 				General.Map.Map.SelectMarkedGeometry(true, true);
 			}
 
+			// If something is highlighted make sure to update the association so that it contains valid data
+			if (highlighted != null && !highlighted.IsDisposed)
+				highlightasso.Set(highlighted);
+
 			UpdateSelectionInfo(); // Update selection info and labels
 			UpdateHelperObjects(); // Update helper lines
 			SetupSectorLabels(); // And sector labels
@@ -586,6 +590,10 @@ namespace CodeImp.DoomBuilder.BuilderModes
 				General.Map.Map.SelectMarkedGeometry(true, true);
 			}
 
+			// If something is highlighted make sure to update the association so that it contains valid data
+			if (highlighted != null && !highlighted.IsDisposed)
+				highlightasso.Set(highlighted);
+
 			UpdateSelectionInfo(); // Update selection info and labels
 			UpdateHelperObjects(); // Update helper lines
 			SetupSectorLabels(); // And sector labels