[webkit-reviews] review granted: [Bug 98144] Fixed position visibility check does not consider descendants : [Attachment 167090] Patch

[bugzilla-daemon at webkit.org]

Simon Fraser (smfr) <simon.fraser at apple.com> has granted Sami Kyöstilä
<skyostil at chromium.org>'s request for review:
Bug 98144: Fixed position visibility check does not consider descendants
https://bugs.webkit.org/show_bug.cgi?id=98144

Attachment 167090: Patch
https://bugs.webkit.org/attachment.cgi?id=167090&action=review

------- Additional Comments from Simon Fraser (smfr) <simon.fraser at apple.com>
View in context: https://bugs.webkit.org/attachment.cgi?id=167090&action=review


> Source/WebCore/rendering/RenderLayerCompositor.cpp:1861
> +    if (FrameView* frameView = m_renderView->frameView()) {
> +	   IntRect viewBounds =
IntRect(IntPoint(frameView->scrollOffsetForFixedPosition()),
frameView->layoutSize());
> +	   if (!layer->absoluteBoundingBox().intersects(viewBounds) &&
!calculateCompositedBounds(layer, rootRenderLayer()).intersects(viewBounds))
> +	       return false;
> +    }

This could be further optimized by having a version of of
calculateCompositedBounds() that is like compositedExtentIntersectsRect() that
you can early-return from as soon as you find something inside the viewport.
But no need to do that now.