Close#39296
Fix an issue that `markDirty()` will not trigger change detection.
The case is for example we have the following component.
```
export class AppComponent implements OnInit {
constructor(private router: Router) {}
ngOnInit() {
this.router.events
.pipe(filter((e) => e instanceof NavigationEnd))
.subscribe(() => ɵmarkDirty(this));
}
}
export class CounterComponent implements OnInit, OnDestroy {
ngOnInit() {
this.countSubject.pipe(takeUntil(this.destroy)).subscribe((count) => {
this.count = count;
ɵmarkDirty(this);
});
}
```
Then the app navigate from `AppComponent` to `CounterComponent`,
so there are 2 `markDirty()` call at in a row.
The `1st` call is from `AppComponent` when router changed, the
`2nd` call is from `CounterComponent.ngOnInit()`.
And the `markDirty()->scheduleTick()` code look like this
```
function scheduleTick(rootContext, flags) {
const nothingScheduled = rootContext.flags === 0 /* Empty */;
rootContext.flags |= flags;
if (nothingScheduled && rootContext.clean == _CLEAN_PROMISE) {
rootContext.schedule(() => {
...
if (rootContext.flags & RootContextFlags.DetectChanges)
rootContext.flags &= ~RootContextFlags.DetectChanges;
tickContext();
rootContext.clean = _CLEAN_PROMISE;
...
});
```
So in this case, the `1st` markDirty() will
1. set rootContext.flags = 1
2. before `tickContext()`, reset rootContext.flags = 0
3. inside `tickContext()`, it will call `CounterComponent.ngOnint()`,
so the `2nd` markDirty() is called.
4. and the `2nd` scheduleTick is called, `nothingScheduled` is true,
but rootContext.clean is not `_CLEAN_PROMISE` yet, since the `1st` markDirty tick
is still running.
5. So nowhere will reset the `rootContext.flags`.
6. then in the future, any other `markDirty()` call will not trigger the tick, since
`nothingScheduled` is always false.
So `nothingScheduled` means no tick is scheduled, `rootContext.clean === _CLEAN_PROMISE`
means no tick is running.
So we should set the flags to `rootContext` only when `no tick is scheudled or running`.
PR Close#39316
4a8d5ae970