Cannot read property "style" of null _rootElement - cdkDrag (drag-drop.es5.js)

[PastoTreering]

What is the expected behavior?

Return out of _pointerMove event (and possibly others, but we're logging _pointerMove crashes only at the moment) if _this._rootElement is null or undefined when dragging without _dropContainer.

What is the current behavior?

_rootElement can be null in the _pointerMove method within drag-drop.es5.js. Throwing an error on line 312 of drag-drop.es5.js when attempting to access "style" of null (_root._rootElement). Possibly event is continuing to fire when parent node has been destroyed or removed?

What are the steps to reproduce?

Unknown, but logs show it is happening mostly on mobile devices (but not exclusively).

Which versions of Angular, Material, OS, TypeScript, browsers are affected?

Angular cdk 7.3.7 +

Is there anything else we should know?

Sorry for the lack of reproducibility, but some safety here for the existence of _rootElement wouldn't hurt imo.

[PastoTreering]

Sentry log:

[crisbeto]

With the current setup I can see how there could be a case where the root element is undefined at the time the dragging starts. I can add some extra guards around it, but it's also possible that the value that is being passed in just isn't resolving to anything. Are you sure that the selector is correct?

[PastoTreering]

Selector looks right to me, I can't actually reproduce the error through my many tests, but we have a lot of error logs coming in reporting it from our users.

[crisbeto]

Is there any information on which browser versions are running into the error?

[PastoTreering]

Here's a broad overview of the usage circumstances. It's mostly on android mobile devices, and chrome browser (mobile and desktop), but not exclusively.

[eLeontev]

Looks like I faced to the same issue. The reason that mentioned is correct. Existed item already was destroyed.

How to reproduce it: just use any custom virtual scroller (ngx-virtual-scroller) which remove not displayed items due to performance reason.

Does anybody have any common solution to fix it?

[denkerny]

+1, happens when drag moving event is on but in container u'd deleted any of item on enter event(for instance).