ASSERTION FAILURE: !oldLast->m_nextSibling in WebFrameProxy::appendChild causing "crashes" on Lion Intel Debug WebKit2 testers

[Jessie Berlin]

void WebFrameProxy::appendChild(WebFrameProxy* child)
{
    ASSERT(child->page() == page());
    ASSERT(!child->m_parentFrame);
    ASSERT(!child->m_nextSibling);
    ASSERT(!child->m_previousSibling);

    child->m_parentFrame = this;

    WebFrameProxy* oldLast = m_lastChild;
    m_lastChild = child;

    if (oldLast) {
        ASSERT(!oldLast->m_nextSibling);
        child->m_previousSibling = oldLast;
        oldLast->m_nextSibling = child;
    } else
        m_firstChild = child;
}

http://build.webkit.org/results/Lion%20Intel%20Debug%20(WebKit2%20Tests)/r111185%20(5032)/fast/frames/iframe-reparenting-unique-name-crash-log.txt

I have to run all fast/frames tests under WKTR to reproduce this locally on my Lion machine - running just fast/frames/iframe-reparenting-unique-name.html is not enough. However, it always seems to "crash" in that test.

[Radar WebKit Bug Importer]

<rdar://problem/11074068>

[Jessie Berlin]

Correction: I can reproduce this locally by just running the fast/frames/iframe-reparenting* tests.

[Alexey Proskuryakov]

Same thing as bug 81453.

*** This bug has been marked as a duplicate of bug 81453 ***