Bug 23233

Summary: Incorrect redraw after layout with transforms
Product: WebKit Reporter: Simon Fraser (smfr) <simon.fraser>
Component: Layout and RenderingAssignee: Simon Fraser (smfr) <simon.fraser>
Status: ASSIGNED    
Severity: Normal CC: hyatt, mitz
Priority: P2    
Version: 528+ (Nightly build)   
Hardware: Mac   
OS: OS X 10.5   
Bug Depends on: 23220    
Bug Blocks:    
Attachments:
Description Flags
Testcase none

Simon Fraser (smfr)
Reported 2009-01-10 23:12:16 PST
Here's another testcase which shows a redraw problem after layout, when there's a transform on an ancestor. Unlike bug 23222, my hunch is that this is caused by layoutDelta doing the wrong thing with transforms.
Attachments
Testcase (835 bytes, text/html)
2009-01-10 23:13 PST, Simon Fraser (smfr) 		no flags
Details
View All Add attachment proposed patch, testcase, etc.
Simon Fraser (smfr)
Comment 1 2009-01-10 23:13:07 PST
Created attachment 26599 [details] Testcase
Simon Fraser (smfr)
Comment 2 2009-01-13 15:59:11 PST
This has nothing to do with layoutDelta. I think the issue is that repaints during layout map the dirty rect through transforms. However, the layer transforms may not have been updated yet (and can depend on the borderBox size, which may also be stale). It's telling that the repainting issue only occurs in the testcase when there is a non-default transform-origin set.
Simon Fraser (smfr)
Comment 3 2009-01-13 16:35:27 PST
hyatt suggests maybe expanding the repaintRect info that layers cache to hold something more complex.
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