Calling `ReactDOMServer.renderToStaticMarkup(elementWithPortal);` gets stuck in a loop while trying to do a static render.

Current behavior:
The behavior can be seen here: https://codepen.io/anon/pen/BmqWOM  by un-commenting line 58 (warning: this will make your tab freeze)

Expected behavior:
It should return with results or throw some kind of error if the input is not valid

return <g>{props.children}</g>;
    }
    ReactDOMServer.renderToStaticMarkup(
      <div>
        <inPUT />
        <svg>
          <CompositeG>
            <linearGradient />
            <foreignObject>
              {}
              <iFrame />
            </foreignObject>
          </CompositeG>
        </svg>