emitter.updateOwnerPos throws an error if emitter is destroyed

[jdoleary]

How to reproduce:

Make an emitter.
emitter.destroy()
emitter.updateOwnerPos(0,0)

It throws an error that can interrupt js execution.

Emitter.ts:491 Uncaught TypeError: Cannot set properties of null (setting 'x')
    at Emitter.updateOwnerPos (Emitter.ts:491:23)

    public updateOwnerPos(x: number, y: number): void
    {
        this._posChanged = true;
        this.ownerPos.x = x; // ERROR OCCURS HERE
        this.ownerPos.y = y;
    }

[andrewstart]

Yes, it is intended that you don't use an emitter after destroying it. If you just wanted all your particles gone but to continue using the emitter, use Emitter.cleanup().

[jdoleary]

Yes, but in the event that it is accidentally used after being destroyed - I would assume it would be better to fail silently or log an error than to throw and interrupt execution?
A simple

if(this.owner){...}

would prevent it from throwing.
This is easy to happen on accident if the emitter is in an array and wasn't removed from the array after being destroyed.