message: Fix a minor crash in the tab widget
diff: @@ -356,6 +356,10 @@ export class TabWidget extends TemplatedElementBase {
  }
  private _scrollTabIntoView(index: number): void {
  + if ( ! this.showTabs) {
  + return;
  + }
  +
  const tabbar = this._getTabbar();
  const item = <HTMLElement> tabbar.children.item(index);
  item.scrollIntoView({
  