Skip the zero-cell moves in the forced wrap separator

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';
           }
 

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`;