Concurrent mode iOS hover behaviour

[subhero24]

I hope this is the place to submit issues regarding concurrent mode.
I don't know if this is a bug or intended behaviour, but I have a situation where the my react app behaves differently depending on the use of concurrent mode.

Here is a link to a codesandbox demo: https://codesandbox.io/s/5xl0vnx11p

The behaviour on mobile Safari on iOS (12.1.2) is different whether using ReactDOM.render vs ReactDOM.createRoot. When ReactDOM.render is used, a tap results in an alert and after the alert is dismissed, the hover styles are applied. When using ReactDOM.createRoot, a tap results in the hover styles being applied. A second tap is needed to invoke the click handler.

(This double tap behaviour from iOS is described here)

Shouldn't the two render methods behave the same in this regard? or is this really intended behaviour?

BTW: A setTimout arround the mouseEnter event handler body does make ReactDOM.createRoot behave the same way as ReactDOM.render

[gaearon]

I think maybe this check doesn't pass because _reactRootContainer field is only used by ReactDOM.render:

react/packages/react-dom/src/client/ReactDOMHostConfig.js

Lines 381 to 388 in db695c4

	const reactRootContainer = container._reactRootContainer;
	if (
	(reactRootContainer === null || reactRootContainer === undefined) &&
	parentNode.onclick === null
	) {
	// TODO: This cast may not be sound for SVG, MathML or custom elements.
	trapClickOnNonInteractiveElement(((parentNode: any): HTMLElement));
	}

[gaearon]

I can't reproduce this anymore. Did iOS change something?

[subhero24]

I also can not reproduce this issue anymore. Guess an iOS update fixed it. Thanks for looking into it!