Should not throw when viewBox isn't present

===

<svg xmlns="http://www.w3.org/2000/svg">
    <path d="M10 10 h 80 v 80 h -80 z"/>
    <path d="M10 -90 h 80 v 80 h -80 z"/>
    <path d="M110 10 h 80 v 80 h -80 z"/>
    <path d="M10 110 h 80 v 80 h -80 z"/>
    <path d="M-90 10 h 80 v 80 h -80 z"/>
</svg>

@@@

<svg xmlns="http://www.w3.org/2000/svg">
    <path d="M10 10 h 80 v 80 h -80 z"/>
    <path d="M10 -90 h 80 v 80 h -80 z"/>
    <path d="M110 10 h 80 v 80 h -80 z"/>
    <path d="M10 110 h 80 v 80 h -80 z"/>
    <path d="M-90 10 h 80 v 80 h -80 z"/>
</svg>