QueryList.changes is triggered for any view changes (even siblings)

🐞 bug report

Affected Package

@angular/core@7.2.14

Is this a regression?

It worked as expected in Version 2.4.9

Description

A QueryList (bound via ViewChildren decorator) is always emitting the changes event even though no of its observed elements have changed. In fact it gets emitted for any view changes within the same view.

🔬 Minimal Reproduction

A minimal example is the following component:

@Component({
	selector: 'querylist-sandbox',
	template: `
		<button (click)="showAddButton = !showAddButton">TOGGLE INPUT</button> 
		<button (click)="itemList.push( itemList.length )" *ngIf="showAddButton">ADD</button>
		<div #items *ngFor="let item of itemList">{{item}}</div>`
})
export class QueryListSandbox {
	@ViewChildren('items')
	private items: QueryList<ElementRef>;
	
	private showAddButton = true;

	private itemList = [ 0, 1, 2 ];

	public constructor() {
		
	}

	public ngAfterViewInit() {
		this.items.changes.subscribe( ql => {
			console.log( ql, 'CHANGES!' );
		});
	}
}

On StackBlitz: https://stackblitz.com/edit/angular-ru9m6u

🔥 Exception or Error

The console log is also made when the TOGGLE button is pressed. I only expect the event to be triggered when i press the ADD button, though.

[Andy1605]

I added the link to a StackBlitz project

[cexbrayat]

@Aleksandyr Awesome, thank you for checking!