Bug 117259 – [CSS Regions] When changing flow-from/flow-into on :hover, elements overflowing the region are not correctly repainted

• Status: RESOLVED
• Resolution: FIXED
• Component: CSS

[Radu Stavila]

Created attachment 203862 [details]
HTML showing the problem

If an element is flowed into a region and it overflows the region, upon changing the region's flow-from to "none" in the :hover style would fail to repaint the portion of the element that was outside of the region. See attached test case.

[Michelangelo De Simone]

Still repros on today's nightly (r151543)

[Max Vujovic]

Changing this bug to block the CSS Regions master bug, not the other way around.

[Radu Stavila]

Created attachment 219639 [details]
Patch

[Antti Koivisto]

Comment on attachment 219639 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=219639&action=review

> Source/WebCore/rendering/RenderRegion.cpp:746
> +        rect.moveBy(baseRect.location());
> +        rect.unite(baseRect);

This pair doesn't look correct. How are rect and baseRect in the same coordinate system in unite()?

[Antti Koivisto]

baseRect is obtained with RenderBlockFlow::clippedOverflowRectForRepaint which at least in theory can have a location that differs from the box location.

[Radu Stavila]

Created attachment 219643 [details]
Simpler approach

[Build Bot]

Comment on attachment 219643 [details]
Simpler approach

Attachment 219643 [details] did not pass mac-wk2-ews (mac-wk2):
Output: http://webkit-queues.appspot.com/results/48758024

New failing tests:
fast/multicol/newmulticol/column-rules-fixed-height.html

[Build Bot]

Created attachment 219654 [details]
Archive of layout-test-results from webkit-ews-11 for mac-mountainlion-wk2

The attached test failures were seen while running run-webkit-tests on the mac-wk2-ews.
Bot: webkit-ews-11  Port: mac-mountainlion-wk2  Platform: Mac OS X 10.8.5

[Radu Stavila]

Created attachment 219744 [details]
Patch fixing failing newmulticol test

[WebKit Commit Bot]

Comment on attachment 219744 [details]
Patch fixing failing newmulticol test

Clearing flags on attachment: 219744

Committed r160905: <http://trac.webkit.org/changeset/160905>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.