Ok, after following down a few rabbit holes, I can with some degree of certainty say that node->renderer()->node() == 0 can only at the end of RenderWidget::destroy(), but that is clearly not the case we're fishing for.
Even if we modify the loop to start at the parent, we're jumping into the render tree to find a node to fire an event on, which is unhealthy for various layering reasons. In summary, to quote the great protagonists from a TV show: "Exterminate! Exterminate!" :DG< On Tue, Sep 14, 2010 at 7:19 PM, Dimitri Glazkov <dglaz...@chromium.org> wrote: > Sounds good, I will look into this. FWIW, when I remove this loop, I > see no regressions in layout tests, including the tests added with the > same commit as the loop. > > :DG< > > On Tue, Sep 14, 2010 at 5:55 PM, Maciej Stachowiak <m...@apple.com> wrote: >> >> On Sep 14, 2010, at 5:41 PM, Dimitri Glazkov wrote: >> >>> Sorry, I meant node->renderer()->node() != 0. My bad. This loop will >>> always exit in in the first iteration. >> >> It definitely is possible for renderers to have a null result from node(). I >> do not know for sure that it's impossible for node->renderer()->node() to be >> null under any circumstances. Anonymous renderers and inline continuations >> are among the ways a null node pointers. It might be that in all such >> circumstances, the renderer won't be returned by any node's renderer() >> method. It would be worth some analysis. >> >> - Maciej >> >>> >>> :DG< >>> >>> On Tue, Sep 14, 2010 at 4:45 PM, Adam Roben <aro...@apple.com> wrote: >>>> On Sep 14, 2010, at 6:46 PM, Dimitri Glazkov wrote: >>>> >>>>> I've been looking at this line here and it doesn't seem to make sense >>>>> to me: >>>>> http://trac.webkit.org/browser/trunk/WebCore/page/EventHandler.cpp#L2153 >>>>> >>>>> It looks like the loop in question will always exit early, because it >>>>> short-circuits to node->renderer()->node() == node, which seems like >>>>> it always will be true. At least, that's what the layout tests say >>>>> when I remove it. >>>> >>>> I don't see anything in that loop that is equivalent to >>>> node->renderer()->node() == node. All I see are null-checks. Note that >>>> line 2154 declares a new variable with the name "node". >>>> >>>> I don't know anything else about this code or what you're asking, though. >>>> >>>> -Adam >>>> >>>> >>> _______________________________________________ >>> webkit-dev mailing list >>> webkit-dev@lists.webkit.org >>> http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev >> >> > _______________________________________________ webkit-dev mailing list webkit-dev@lists.webkit.org http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev