Bug 20047

Summary: Incorrect rendering during opacity transition on element with positioned children
Product: WebKit Reporter: Simon Fraser (smfr) <simon.fraser>
Component: Layout and RenderingAssignee: Simon Fraser (smfr) <simon.fraser>
Status: RESOLVED FIXED    
Severity: Normal CC: dino, hyatt
Priority: P2    
Version: 528+ (Nightly build)   
Hardware: Mac   
OS: OS X 10.5   
Attachments:
Description Flags
Testcase
none
Better testcase; reveals stacking context
none
Patch (with some FIXMES)
none
Patch, testcase, changelogs hyatt: review+

Simon Fraser (smfr)
Reported 2008-07-15 16:30:02 PDT
In the attached testcase, a positioned element runs a transition when its opacity changes on :hover. However, a child element which is positioned snaps to the final opacity, without showing the transition, which is wrong. This only happens if: * the child is positioned * the target opacity is 1 I think it's related to stacking context changes when opacity hits 1.
Attachments
Testcase (954 bytes, text/html)
2008-07-15 16:30 PDT, Simon Fraser (smfr) 		no flags
Details
Better testcase; reveals stacking context (1.61 KB, text/html)
2008-07-15 16:58 PDT, Simon Fraser (smfr) 		no flags
Details
Patch (with some FIXMES) (1.54 KB, patch)
2008-07-15 17:04 PDT, Simon Fraser (smfr) 		no flags
DetailsFormatted DiffDiff
Patch, testcase, changelogs (5.02 KB, patch)
2008-07-16 15:48 PDT, Simon Fraser (smfr) 		hyatt: review+
DetailsFormatted DiffDiff
Show Obsolete (2) View All Add attachment proposed patch, testcase, etc.
Simon Fraser (smfr)
Comment 1 2008-07-15 16:30:25 PDT
Created attachment 22293 [details] Testcase
Simon Fraser (smfr)
Comment 2 2008-07-15 16:58:30 PDT
Created attachment 22295 [details] Better testcase; reveals stacking context
Simon Fraser (smfr)
Comment 3 2008-07-15 17:04:19 PDT
Created attachment 22296 [details] Patch (with some FIXMES)
Dave Hyatt
Comment 4 2008-07-15 19:35:17 PDT
Comment on attachment 22296 [details] Patch (with some FIXMES) The property has to blend in order for this problem to be exposed. I think you only need the opacity and transform checks.
Simon Fraser (smfr)
Comment 5 2008-07-16 15:48:02 PDT
Created attachment 22321 [details] Patch, testcase, changelogs
Dave Hyatt
Comment 6 2008-07-16 15:55:46 PDT
Comment on attachment 22321 [details] Patch, testcase, changelogs r=me
Dean Jackson
Comment 7 2008-07-16 18:16:51 PDT
Committing to http://svn.webkit.org/repository/webkit/trunk ... M LayoutTests/ChangeLog A LayoutTests/transitions/opacity-transition-zindex-expected.txt A LayoutTests/transitions/opacity-transition-zindex.html M WebCore/ChangeLog M WebCore/page/AnimationController.cpp Committed r35207
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