[webkit-reviews] review requested: [Bug 9749] A nested content editable div causes unnecessary screen redraws. : [Attachment 9243] patch

[bugzilla-request-daemon at opendarwin.org]

Beth Dakin <bdakin at apple.com> has asked Dave Hyatt <hyatt at apple.com> for
review:
Bug 9749: A nested content editable div causes unnecessary screen redraws.
http://bugzilla.opendarwin.org/show_bug.cgi?id=9749

Attachment 9243: patch
http://bugzilla.opendarwin.org/attachment.cgi?id=9243&action=edit

------- Additional Comments from Beth Dakin <bdakin at apple.com>
I feel like this patch could not possibly be right. But it definitely hunts
down the source of the problem. I remembered fixing a bug a while ago where the
root cause was that a bunch of our old code held assumptions that positioned
elements would always have line boxes, but it turns out that this isn't true.
This assumption is also causing extra repaints because in
layoutInlineChildren() we set fullLayout to true if we don't have any line
boxes...meaning that positioned elements without line boxes always get a full
layout. This is clearly overzealous. I imagine that the patch I attached is
undezealous. (underzealous?? forgive me, for it has been a long day.) But I
figure that attaching it is a good way to start a discussion about what the
right fix is. Thoughts?