REGRESSION: Some bit garbage left behind on cnn story page after banner ad appears

• Component: Layout and Rendering
• Status: RESOLVED FIXED

[John Sullivan]

To reproduce:
1. visit http://www.cnn.com
2. click one of the story titles in the "LATEST NEWS" section

Watch the page as it loads. First the entire contents of the page load, and look correct. A moment later, a banner ad appears at the top of the page, and the rest of the page shifts down. When this happens, a few pixels from the left side of the first character in the headline of the story are left behind in their previous position, about an inch above their new position. The first char in the headline is now slightly clipped on the left.

This did not occur on shipping Safari.

[John Sullivan]

Created attachment 10604 [details]
Screenshot showing problem

In the attached screenshot, the "S" from "Shoppers" is slightly clipped on the left, and the missing bits are to the left of the blue background behind "Home World U.S.".

Created attachment 10631 [details]
Reduction - strict mode

Created attachment 10632 [details]
Reduction - quirks mode

This test case is broken in shipping Safari as well as in TOT

[John Sullivan]

Maybe the test case is reflecting a different issue then? The bit garbage problem I see does not occur on shipping Safari.

Comment on attachment 10631 [details]
Reduction - strict mode

(In reply to comment #4)
> Maybe the test case is reflecting a different issue then? The bit garbage
> problem I see does not occur on shipping Safari.
> 

The "strict mode" flavor of the bug *is* a regression. I think that explains the regression on cnn.com.

*** Bug 11045 has been marked as a duplicate of this bug. ***

Also failing manual-tests/left-overflow-repaint.html because of this. As noted in bug 11045, the problem is that tables' repaint rects don't account for cells' overflow.

[Stephanie Lewis]

radar 4823134

Fixed by fixing bug 12079 and bug 12123.

Reopening because r19588 was rolled out.