here is an app https://gist.github.com/gre/52e28f74eda0beccc17e880efe18c250
There is intentionally a bug in this app: the App component returns `<Demo setVariables={v=>this.setState(..)} variables={..} />` and `Demo` calls `setVariables` in componentDidMount and componentWillReceiveProps (it shouldn't, this is bad user code). What this issue raises is a regression behaviour in React 16 compared to 15.


in React 15 : it renders but you directly get a `Uncaught RangeError: Maximum call stack size exceeded`.
in React 16 : nothing renders, the app never loads and the browser is spinning forever! I think React is stuck in an infinite recursion.

I presume this is because fiber is by nature async. The fact things never ends makes it very hard to investigate and isolate the source of the problem in a large codebase.
should there be some sort of maximum call stack in Fiber ?

> Context: When we migrated our app to latest React Native recently, we had a weird freezing case: the app was completely unresponsive (no button works) but you could still do native actions like scroll a ScrollView. however, even the RN devtool menu action was not working (like the inspector) – probably because it involves JS and React was just stuck in this recursion loop.
In our case, the issue was because calling `relay.setVariables` in lifecycle but with a wrong logic. for some reason our code used to work in the past but now creates this recursion loop.
mounts++;
        
        if (!this.props.rendered) {
          this.props.onChange({rendered: true});
        }
      }
    }
    var container = document.createElement('div');
    function render() {
      ReactDOM.render(
        <Editor
          onChange={newProps => {
            props = {...props, ...newProps};
            render();
          }}
          {...props}
        />,
        container,
      );
    }
    var props = {text: 'hello', rendered: false};
    render();
    props = {...props, text: 'goodbye'};
    render();
    expect(container.textContent).toBe('goodbye');
    expect(mounts).toBe(1);
  });
  it('mounts and unmounts are sync even in a batch', () => {
    var ops = [];