Observed this on react@16.0.0-beta.5

```js
import React from 'react';
import { renderToString } from 'react-dom/server';

const B = () => 'b';

console.log(renderToString(<div>{'a'}<B />{'c'}</div>));
```

This renders as `<div data-reactroot="">a<!-- -->bc</div>`. If you try to hydrate this you'll get the error: Text content did not match. Server: "bc" Client: "b".
}
    }
    if (__DEV__) {
      validatePropertiesInDevelopment(tag, props);
    }
    assertValidProps(tag, props);
    var out = createOpenTagMarkup(
      element.type,
      tag,
      props,
      namespace,
      this.makeStaticMarkup,
      this.stack.length === 1,
      null,
    );
    var footer = '';
    if (omittedCloseTags.hasOwnProperty(tag)) {
      out += '/>';
    } else {
      out += '>';
      footer = '</' + element.type + '>';
    }
    var children;
    var innerMarkup = getNonChildrenInnerMarkup(props);
    if (innerMarkup != null) {
      children = [];
      if (newlineEatingTags[tag] && innerMarkup.charAt(0) === '\n') {