From 5a19e70c0572c310c5b866a46ac66b16b22ec561 Mon Sep 17 00:00:00 2001
From: biwa <6475593+biwa@users.noreply.github.com>
Date: Sun, 5 Sep 2021 11:06:50 +0200
Subject: [PATCH] Visual Mode: added some safeguards against potential crashes
 that should never happen. Potentially fixes #614

---
 Source/Plugins/BuilderModes/VisualModes/BaseVisualMode.cs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Source/Plugins/BuilderModes/VisualModes/BaseVisualMode.cs b/Source/Plugins/BuilderModes/VisualModes/BaseVisualMode.cs
index 8dfdac56..1ae257f0 100755
--- a/Source/Plugins/BuilderModes/VisualModes/BaseVisualMode.cs
+++ b/Source/Plugins/BuilderModes/VisualModes/BaseVisualMode.cs
@@ -1390,8 +1390,8 @@ namespace CodeImp.DoomBuilder.BuilderModes
 					if (ld.IsDisposed)
 						continue;
 
-					if (ld.Front != null && !ld.Front.Sector.IsDisposed) vertexsectors.Add(ld.Front.Sector);
-					if (ld.Back != null && !ld.Front.Sector.IsDisposed) vertexsectors.Add(ld.Back.Sector);
+					if (ld.Front != null && ld.Front.Sector != null && !ld.Front.Sector.IsDisposed) vertexsectors.Add(ld.Front.Sector);
+					if (ld.Back != null && ld.Back.Sector != null && !ld.Back.Sector.IsDisposed) vertexsectors.Add(ld.Back.Sector);
 				}
 
 				foreach(Sector s in vertexsectors)