Merge pull request #5390 from xtermjs/anthonykim1/fixTeleportAltBuffer

Fix scrollbar teleport after exiting alt buffer

src/common/TestUtils.test.ts

@@ -20,6 +20,7 @@ export class MockBufferService implements IBufferService {
   public buffers: IBufferSet = {} as any;
   public onResize: Event<{ cols: number, rows: number }> = new Emitter<{ cols: number, rows: number }>().event;
   public onScroll: Event<number> = new Emitter<number>().event;
+  private readonly _onScroll = new Emitter<number>();
   public isUserScrolling: boolean = false;
   constructor(
     public cols: number,
@@ -27,6 +28,10 @@ export class MockBufferService implements IBufferService {
     optionsService: IOptionsService = new MockOptionsService()
   ) {
     this.buffers = new BufferSet(optionsService, this);
+    // Listen to buffer activation events and automatically fire scroll events
+    this.buffers.onBufferActivate(e => {
+      this._onScroll.fire(e.activeBuffer.ydisp);
+    });
   }
   public scrollPages(pageCount: number): void {
     throw new Error('Method not implemented.');

src/common/services/BufferService.ts

@@ -37,6 +37,9 @@ export class BufferService extends Disposable implements IBufferService {
     this.cols = Math.max(optionsService.rawOptions.cols || 0, MINIMUM_COLS);
     this.rows = Math.max(optionsService.rawOptions.rows || 0, MINIMUM_ROWS);
     this.buffers = this._register(new BufferSet(optionsService, this));
+    this._register(this.buffers.onBufferActivate(e => {
+      this._onScroll.fire(e.activeBuffer.ydisp);
+    }));
   }
 
   public resize(cols: number, rows: number): void {