From 4f376a4323023e16b8521c484dbd13373538648f Mon Sep 17 00:00:00 2001
From: WMJ <wmj@live.cn>
Date: Fri, 21 Jan 2022 10:34:37 +0800
Subject: [PATCH] - Fixed scrollbar margins crashing VS 17.1 preview 3

---
 Codist/Margins/CommentMarginElement.cs | 2 +-
 Codist/Margins/LineNumberMargin.cs     | 2 +-
 Codist/Margins/SelectionMargin.cs      | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/Codist/Margins/CommentMarginElement.cs b/Codist/Margins/CommentMarginElement.cs
index 8ea7506d..c2b505d6 100644
--- a/Codist/Margins/CommentMarginElement.cs
+++ b/Codist/Margins/CommentMarginElement.cs
@@ -168,7 +168,7 @@ void OnMappingChanged(object sender, EventArgs e) {
 		/// <param name="drawingContext">The <see cref="DrawingContext"/> used to render the margin.</param>
 		protected override void OnRender(DrawingContext drawingContext) {
 			base.OnRender(drawingContext);
-			if (_TextView.IsClosed == false && _Tags.HasTag) {
+			if (_TextView?.IsClosed != false && _Tags.HasTag) {
 				DrawMarkers(drawingContext);
 			}
 		}
diff --git a/Codist/Margins/LineNumberMargin.cs b/Codist/Margins/LineNumberMargin.cs
index e3560c32..80c48819 100644
--- a/Codist/Margins/LineNumberMargin.cs
+++ b/Codist/Margins/LineNumberMargin.cs
@@ -86,7 +86,7 @@ void OnMappingChanged(object sender, EventArgs e) {
 		/// <param name="drawingContext">The <see cref="DrawingContext"/> used to render the margin.</param>
 		protected override void OnRender(DrawingContext drawingContext) {
 			base.OnRender(drawingContext);
-			if (_TextView.IsClosed) {
+			if (_TextView?.IsClosed != false) {
 				return;
 			}
 			if (Config.Instance.MarkerOptions.MatchFlags(MarkerOptions.LineNumber)) {
diff --git a/Codist/Margins/SelectionMargin.cs b/Codist/Margins/SelectionMargin.cs
index 26029420..e3aa0e2a 100644
--- a/Codist/Margins/SelectionMargin.cs
+++ b/Codist/Margins/SelectionMargin.cs
@@ -103,7 +103,7 @@ void OnMappingChanged(object sender, EventArgs e) {
 		/// <param name="drawingContext">The <see cref="DrawingContext"/> used to render the margin.</param>
 		protected override void OnRender(DrawingContext drawingContext) {
 			base.OnRender(drawingContext);
-			if (_TextView.IsClosed) {
+			if (_TextView?.IsClosed != false) {
 				return;
 			}
 			if (Config.Instance.MarkerOptions.MatchFlags(MarkerOptions.Selection)) {