Bug 106712

Summary: Fixed elements jiggle during scroll on some sites that cause layouts with an onscroll handler
Product: WebKit Reporter: Beth Dakin <bdakin>
Component: Layout and RenderingAssignee: Nobody <webkit-unassigned>
Status: NEW ---    
Severity: Normal CC: bdakin, simon.fraser
Priority: P2    
Version: 528+ (Nightly build)   
Hardware: Unspecified   
OS: Unspecified   
URL: http://www.redfin.com/CA/Mountain-View/1075-Space-Park-Way-94043/unit-297/home/21854852
Attachments:
Description Flags
Test case none

Description Beth Dakin 2013-01-11 15:38:54 PST 
This affects redfin.com and possibly other sites as well. Reduction attached.

If you scroll the test case, the green box sometimes jiggles inappropriately. The test has Javascript that runs during an onscroll handler which forces a layout. I believe that the jiggling is happening because the main thread doesn't have the updated scroll position from the scrolling thread.

I'm not sure how to address this problem.
Comment 1 Beth Dakin 2013-01-11 15:39:43 PST 
Created attachment 182436 [details]
Test case
Comment 2 Beth Dakin 2013-01-11 15:41:38 PST 
This is probably the same as <rdar://problem/12723953>