From 3d69482c37497b50c2fece5cb9afe10009b2809c Mon Sep 17 00:00:00 2001
From: David Wilson <david.wilson@codesignal.com>
Date: Thu, 15 Oct 2026 13:01:41 +0300
Subject: [PATCH] Skip the zero-cell moves in the forced wrap separator

When the row before a forced wrap has no content, the moves around the
erase were written as `CSI 0 C` and `CSI 0 D`. A count of 0 means 1, so
the erase started one cell late and left the first dash on screen. Now
the moves are left out when there's nothing to move past.

Fixes #6231
---
 addons/addon-serialize/src/SerializeAddon.ts     | 10 ++++++++--
 .../addon-serialize/test/SerializeAddon.test.ts  | 16 ++++++++++++++++
 2 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/addons/addon-serialize/src/SerializeAddon.ts b/addons/addon-serialize/src/SerializeAddon.ts
index e1728feb21..c8a1c72fd2 100644
--- a/addons/addon-serialize/src/SerializeAddon.ts
+++ b/addons/addon-serialize/src/SerializeAddon.ts
@@ -250,10 +250,16 @@ class StringSerializeHandler extends BaseSerializeHandler {
 
           if (this._nullCellCount > 0) {
             // do these because we filled the last several null slot, which we shouldn't
+            // a move of 0 means a move of 1, so skip the moves when the row has no content
+            const contentLength = currentLine.length - this._nullCellCount;
             rowSeparator += '\u001b[A';
-            rowSeparator += `\u001b[${currentLine.length - this._nullCellCount}C`;
+            if (contentLength > 0) {
+              rowSeparator += `\u001b[${contentLength}C`;
+            }
             rowSeparator += `\u001b[${this._nullCellCount}X`;
-            rowSeparator += `\u001b[${currentLine.length - this._nullCellCount}D`;
+            if (contentLength > 0) {
+              rowSeparator += `\u001b[${contentLength}D`;
+            }
             rowSeparator += '\u001b[B';
           }
 
diff --git a/addons/addon-serialize/test/SerializeAddon.test.ts b/addons/addon-serialize/test/SerializeAddon.test.ts
index f84452d58b..21a24e9122 100644
--- a/addons/addon-serialize/test/SerializeAddon.test.ts
+++ b/addons/addon-serialize/test/SerializeAddon.test.ts
@@ -520,6 +520,22 @@ test.describe('SerializeAddon', () => {
     await testNormalScreenEqual(ctx.page, segments.join(''));
   });
 
+  test('handle empty row followed by wrapped row', async () => {
+    const CLEAR_RIGHT = (l: number): string => `\u001b[${l}X`;
+    const MOVE_TO = (row: number, col: number): string => `\u001b[${row};${col}H`;
+
+    // The wrap is forced with a row of dashes. With no content in the row, the
+    // moves around the erase have a count of 0, which means 1.
+    const segments = [
+      'abcdefghijXYZ',
+      MOVE_TO(1, 1),
+      CLEAR_RIGHT(10),
+      MOVE_TO(2, 4)
+    ];
+
+    await testNormalScreenEqual(ctx.page, segments.join(''));
+  });
+
   test('handle invalid wrap after scroll', async () => {
     const CLEAR_RIGHT = (l: number): string => `\u001b[${l}X`;
     const MOVE_UP = (l: number): string => `\u001b[${l}A`;