Don't use intrinsic width if our container's width is zero.
Since at least r798 we use a replaced element's intrinsic width if its
containing block has a width of zero. As a result our rendering of
width100percent-image.html has disagreed with all other browsers
(IE10, FF29, and Opera(Presto)) and
we display replaced elements when they should be invisible.
If our container has zero width then let our width be zero too.