From dc6da7baa5be6ff39ed6ff9141b0c8bd446d8960 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=B6ran=20Karl?=
 <3951388+JoeKar@users.noreply.github.com>
Date: Fri, 5 Apr 2024 10:50:45 +0200
Subject: [PATCH] buffer: Lock line modifications within `Retab()`

---
 internal/buffer/buffer.go | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/internal/buffer/buffer.go b/internal/buffer/buffer.go
index 35e650fd05..6e0dea0886 100644
--- a/internal/buffer/buffer.go
+++ b/internal/buffer/buffer.go
@@ -1167,9 +1167,14 @@ func (b *Buffer) Retab() {
 	tabsize := util.IntOpt(b.Settings["tabsize"])
 	dirty := false
 
-	for i := 0; i < b.LinesNum(); i++ {
-		l := b.LineBytes(i)
+	for i := 0; ; i++ {
+		b.Lock()
+		if i >= b.LinesNum() {
+			b.Unlock()
+			break
+		}
 
+		l := b.LineBytes(i)
 		ws := util.GetLeadingWhitespace(l)
 		if len(ws) != 0 {
 			if toSpaces {
@@ -1181,6 +1186,8 @@ func (b *Buffer) Retab() {
 
 		l = bytes.TrimLeft(l, " \t")
 		b.lines[i].data = append(ws, l...)
+		b.Unlock()
+
 		b.MarkModified(i, i)
 		dirty = true
 	}