fix #3641

src/common/buffer/Buffer.ts

@@ -585,12 +585,17 @@ export class Buffer implements IBuffer {
     return x >= this._cols ? this._cols - 1 : x < 0 ? 0 : x;
   }
 
-  public clearMarkers(): void {
+  public clearMarkers(y?: number): void {
     this._isClearing = true;
-    for (const marker of this.markers) {
-      marker.dispose();
-    }
-    this.markers = [];
+    if (y) {
+      for (const marker of this.markers.filter(m => m.line === y)) {
+        marker.dispose();
+      }
+    } else {
+      for (const marker of this.markers) {
+        marker.dispose();
+      }
+    } 
     this._isClearing = false;
   }