Merge pull request #8129 from mono/backport-pr-8073-to-release-8.2

[release-8.2] Fix 935197: Exception in TextFileNavigationPoint.OnDocumentClosing

1 files changed, 18 insertions, 17 deletions

diff --git a/main/src/core/MonoDevelop.Ide/MonoDevelop.Ide.Navigation/TextFileNavigationPoint.cs b/main/src/core/MonoDevelop.Ide/MonoDevelop.Ide.Navigation/TextFileNavigationPoint.cs
index a59fbe4ef3..29838a4e3f 100644
--- a/main/src/core/MonoDevelop.Ide/MonoDevelop.Ide.Navigation/TextFileNavigationPoint.cs
+++ b/main/src/core/MonoDevelop.Ide/MonoDevelop.Ide.Navigation/TextFileNavigationPoint.cs
@@ -48,22 +48,21 @@ namespace MonoDevelop.Ide.Navigation
 		int column;
 
 		SnapshotPoint? offset;
-		ITextView textView;
 
 		public TextFileNavigationPoint (Document doc, ITextView textView)
 			: base (doc)
 		{
 			offset = textView.Caret.Position.BufferPosition;
-			this.textView = textView;
 		}
 
 		protected override void OnDocumentClosing ()
 		{
 			try {
 				// text source version becomes invalid on document close.
-				if (textView != null && this.offset.HasValue) {
-					var translatedOffset = this.offset.Value.TranslateTo (textView.TextSnapshot, PointTrackingMode.Positive);
-					var snapshotLine = textView.TextSnapshot.GetLineFromPosition (translatedOffset);
+				if (this.offset is SnapshotPoint point) {
+					var currentSnapshot = point.Snapshot.TextBuffer.CurrentSnapshot;
+					var translatedOffset = point.TranslateTo (currentSnapshot, PointTrackingMode.Positive);
+					var snapshotLine = currentSnapshot.GetLineFromPosition (translatedOffset);
 					line = snapshotLine.LineNumber;
 					column = translatedOffset - snapshotLine.Start.Position;
 					offset = null;
@@ -71,7 +70,6 @@ namespace MonoDevelop.Ide.Navigation
 			} catch (Exception e) {
 				LoggingService.LogInternalError (e);
 			}
-			textView = null;
 		}
 
 		public TextFileNavigationPoint (FilePath file, int line, int column)
@@ -87,14 +85,16 @@ namespace MonoDevelop.Ide.Navigation
 			if (tf == null)
 				return false;
 			var line1 = this.line;
-			if (this.offset is SnapshotPoint sp1 && sp1.Snapshot.TextBuffer == textView?.TextBuffer) {
-				var translatedOffset1 = sp1.TranslateTo (textView.TextSnapshot, PointTrackingMode.Positive);
-				line1 = textView.TextSnapshot.GetLineNumberFromPosition (translatedOffset1);
+			if (this.offset is SnapshotPoint sp1) {
+				var currentSnapshot = sp1.Snapshot.TextBuffer.CurrentSnapshot;
+				var translatedOffset1 = sp1.TranslateTo (currentSnapshot, PointTrackingMode.Positive);
+				line1 = currentSnapshot.GetLineNumberFromPosition (translatedOffset1);
 			}
 			var line2 = tf.line;
-			if (tf.offset is SnapshotPoint sp2 && sp2.Snapshot.TextBuffer == textView?.TextBuffer) {
-				var translatedOffset2 = sp2.TranslateTo (textView.TextSnapshot, PointTrackingMode.Positive);
-				line2 = textView.TextSnapshot.GetLineNumberFromPosition (translatedOffset2);
+			if (tf.offset is SnapshotPoint sp2) {
+				var currentSnapshot = sp2.Snapshot.TextBuffer.CurrentSnapshot;
+				var translatedOffset2 = sp2.TranslateTo (currentSnapshot, PointTrackingMode.Positive);
+				line2 = currentSnapshot.GetLineNumberFromPosition (translatedOffset2);
 			}
 			return base.Equals (tf) && Math.Abs (line1 - line2) < 5;
 		}
@@ -131,12 +131,13 @@ namespace MonoDevelop.Ide.Navigation
 			var editorOperationsFactoryService = CompositionManager.Instance.GetExportedValue<IEditorOperationsFactoryService> ();
 			var editorOperations = editorOperationsFactoryService.GetEditorOperations (textView);
 			VirtualSnapshotPoint point;
-			if (textView == this.textView && offset.HasValue) {
-				var sp = offset.Value.TranslateTo (textView.TextSnapshot, PointTrackingMode.Positive);
-				point = new VirtualSnapshotPoint (textView.TextSnapshot, sp);
+			if (offset is SnapshotPoint sp1 && sp1.Snapshot.TextBuffer == textView.TextBuffer) {
+				var currentSnapshot = textView.TextBuffer.CurrentSnapshot;
+				var sp = sp1.TranslateTo (currentSnapshot, PointTrackingMode.Positive);
+				point = new VirtualSnapshotPoint (currentSnapshot, sp);
 			} else {
-				var snapshotLine = textView.TextSnapshot.GetLineFromLineNumber (this.line);
-				point = new VirtualSnapshotPoint (textView.TextSnapshot, snapshotLine.Start.Position + column);
+				var snapshotLine = textView.TextSnapshot.GetLineFromLineNumber (Math.Min (textView.TextSnapshot.LineCount - 1, this.line));
+				point = new VirtualSnapshotPoint (textView.TextSnapshot, Math.Min (textView.TextSnapshot.Length - 1, snapshotLine.Start.Position + column));
 				offset = point.Position;
 			}
 			editorOperations.SelectAndMoveCaret (point, point, TextSelectionMode.Stream, EnsureSpanVisibleOptions.AlwaysCenter);