JSFiddle - React, Tailwind, and code Playground

HTML

<div id="extra"></div>
<input type="file" id="test">
<p>
To reproduce error - Click on the input box portion of the file input and select any file
</p>

JavaScript

var test = document.getElementById("test");
test.addEventListener("focus", onfocus);
test.addEventListener("change", onchange);

function onfocus(event) {
    console.log(document.activeElement === test, document.activeElement);
}

function onchange( event ) {
    // to show the bug in http://jqbug.com/ui/8288
    var active = document.activeElement,
        extra = document.getElementById("extra");
    console.log( "change:", active );
    extra.appendChild( test );
    // boom!
    extra.contains( active );
}