Bug 41701 - Parts of page disappear
Summary: Parts of page disappear
Alias: None
Product: WebKit
Classification: Unclassified
Component: Layout and Rendering (show other bugs)
Version: 528+ (Nightly build)
Hardware: Mac OS X 10.6
: P2 Normal
Assignee: Nobody
Keywords: InRadar
Depends on:
Reported: 2010-07-06 09:03 PDT by Nathan Lawrence
Modified: 2010-12-14 17:53 PST (History)
3 users (show)

See Also:

Patch (10.98 KB, patch)
2010-12-14 17:43 PST, Simon Fraser (smfr)
cmarrin: review+
Details | Formatted Diff | Diff

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Description Nathan Lawrence 2010-07-06 09:03:58 PDT
Steps to reproduce:

1) Visit http://inhabitat.com/2010/06/29/university-of-michigan-solar-car-team-wins-american-solar-challenge/
2) Scroll down below the header of the page
3) Let the page sit for a few minutes
4) Scroll back up, the header is gone.
Comment 1 Alexey Proskuryakov 2010-07-06 12:56:37 PDT
I cannot reproduce this with Safari 5.0 on Snow Leopard.

Could you please describe your configuration (OS, Safari and Flash versions, 64 bit or 32 bit)? Is this reliably reproducible? Does this happen with Flash disabled?
Comment 2 Nathan Lawrence 2010-07-06 13:45:13 PDT
After investigating further, this problem seems to involve plugins.  It is unnecessary to scroll down on the page to cause the header to disappear.  Disabling plugins seems to cause the problem to go away.  After the header has disappeared, if you turn plugins off, the header will reappear, and then disappear when plugins are turned back on.

I'm running 64bit Safari 5.0 on Snow Leopard.  It seems to alternate between the entire header disappearing, and just the logo in the upper left disappearing.  I have also confirmed that the problem exists on the r62241 nightly build for Snow Leopard.
Comment 3 Nathan Lawrence 2010-07-06 13:58:46 PDT
The version of flash that I am running (http://kb2.adobe.com/cps/155/tn_15507.html) is 10,1,53,64.
Comment 4 Simon Fraser (smfr) 2010-07-06 14:12:07 PDT
Comment 5 Simon Fraser (smfr) 2010-07-06 14:19:48 PDT
Does this happen with TOT?
Comment 6 Nathan Lawrence 2010-07-07 08:41:55 PDT
Running on a debug build of revision 62596 (2010-07-06 14:21:37), the problem still seems to occur.
Comment 7 Simon Fraser (smfr) 2010-12-14 17:43:32 PST
Created attachment 76601 [details]
Comment 8 Chris Marrin 2010-12-14 17:50:24 PST
Comment on attachment 76601 [details]

View in context: https://bugs.webkit.org/attachment.cgi?id=76601&action=review

> LayoutTests/compositing/geometry/limit-layer-bounds-opacity-transition.html:64
> +</html>

Since this test involves video (and it looks like a plugin is required to tickle the bug), shouldn't it have plugin or video in the name?

> WebCore/rendering/RenderLayerBacking.cpp:1156
> +    return didAnimateTransform || didAnimateOpacity;

Yeah, much better logic
Comment 9 Simon Fraser (smfr) 2010-12-14 17:53:00 PST