<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"> <!-- this is a test for https://bugzilla.mozilla.org/show_bug.cgi?id=521682 --> <defs> <svg id="d"> <rect height="50%" width="100%" fill="blue" /> </svg> </defs> <use id="u" xlink:href="#d" height="100%" /> </svg>