I'm unsure if this is a bug, but for a given webpage, calling LegacyWebArchive::create(Frame*) does not generate the same webarchive content as LegacyWebArchive::create(Node*) where the webpage's main frame is passed to the former, and the webpage's main frame's document node is passed to the latter. this is observable if you try to create a webarchive of a page with iframes, like one's facebook homepage via LegacyWebArchive::create(Frame*) instead of LegacyWebArchive::create(Node*). I've checked throughout the webkit opensource projects that are built on mac, and it seems that the only place we use LegacyWebArchive::create(Frame*) is from DumpRenderTree::dump(), in the case for "dumpSourceAsWebArchive".