Firefox bug: Incorrect getScreenCTM when parent div is transformed

HTML

<div id="container">
    <svg id="svg" width="100" height="100">
        <rect fill="red" width="100" height="100"></rect>
    </svg>
</div>

CSS

#container {
  /*-webkit-transform: translateX(50px);
          transform: translateX(50px);*/
}

JavaScript

var container = document.querySelector("#container");
var svg = document.querySelector("#svg");

var topLeft = svg.createSVGPoint(0, 0);
var screenPosition = topLeft.matrixTransform(svg.getScreenCTM());

// Should print ~58
console.log(screenPosition.x);