(I am using 15rc2 because I need all the svg tags)

I am rendering a foreignObject svg tag. According to [MDN](https://developer.mozilla.org/en-US/docs/Web/SVG/Element/foreignObject) I put body tag inside that tag and then whatever html I want in there.

``` html
<foreignObject>
  <body xmlns="http://www.w3.org/1999/xhtml">
   <!-- whatever html I want -->
  </body>
</foreignObject>
```

renderToString on the server leaves the body tag in place, and gives it a react-dataid. However when rendered on the client that body tag is removed. So when I look at the live elements, the body inside foreignObjects is gone, along with it's data-reactid.  The server source ( ie view page source ) shows that the body tag was rendered with the missing react-dataid.

The result is that you get a “Invariant Violation: Unable to find element with ID XX”, when the page updates, and somethings don't work.

Removing the body from inside the foreignObject tag seems to solve the problem, 

``` html
<foreignObject>
   <!-- whatever html I want -->
</foreignObject>
```

but I don't know if that is an "OK" solution to this or if that body tag is necessary in some scenarios.  But in either case this seems to be a scenario where server rendering results in different DOM/HTML then client rendering.

Is this a problem, or is the body tag not supposed to there anyway?

Todd

var specialTags = [
    'address', 'applet', 'area', 'article', 'aside', 'base', 'basefont',
    'bgsound', 'blockquote', 'body', 'br', 'button', 'caption', 'center', 'col',
    'colgroup', 'dd', 'details', 'dir', 'div', 'dl', 'dt', 'embed', 'fieldset',
    'figcaption', 'figure', 'footer', 'form', 'frame', 'frameset', 'h1', 'h2',
    'h3', 'h4', 'h5', 'h6', 'head', 'header', 'hgroup', 'hr', 'html', 'iframe',
    'img', 'input', 'isindex', 'li', 'link', 'listing', 'main', 'marquee',
    'menu', 'menuitem', 'meta', 'nav', 'noembed', 'noframes', 'noscript',
    'object', 'ol', 'p', 'param', 'plaintext', 'pre', 'script', 'section',
    'select', 'source', 'style', 'summary', 'table', 'tbody', 'td', 'template',
    'textarea', 'tfoot', 'th', 'thead', 'title', 'tr', 'track', 'ul', 'wbr',
    'xmp',
  ];
  
  var inScopeTags = [
    'applet', 'caption', 'html', 'table', 'td', 'th', 'marquee', 'object',
    'template',