http://www.w3.org/TR/css3-linebox/#line-height

[#d01] This is a div in which resides a paragraph. The line-height of the div has been increased to one-and-one-half times the font size of the div.

This is the paragrph. It should use the same line-height as the div even though its font size is much smaller and it starts out with an even smaller line-height. The latter should be overridden by 'none'.