Steps to reproduce: 1. Navigate to https://software.hixie.ch/utilities/js/live-dom-viewer/?%3C!DOCTYPE%20html%3E%0A%3Cinput%20type%3Dfoobar%3E%0A%3Cscript%3E%0Aonclick%20%3D%20()%20%3D%3E%20document.querySelector(%60input%60).type%20%3D%20%60checkbox%60%0A%3C%2Fscript%3E 2. Click in the nested document with the label "Rendered view" (for instance, next to the checkbox) Expected: a checkbox. Actual: a checkbox with behind it the remnants of a text box.
<rdar://problem/117904003>
This appears to have been fixed.