Summary: | REGRESSION (r128787): Fixed position div causes other elements to not update correctly | ||||||||||
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Product: | WebKit | Reporter: | Kevin M. Dean <kevin> | ||||||||
Component: | WebCore Misc. | Assignee: | Simon Fraser (smfr) <simon.fraser> | ||||||||
Status: | ASSIGNED --- | ||||||||||
Severity: | Normal | CC: | bdakin, cabanier, dglazkov, enne, eric, jchaffraix, simon.fraser, thorton, webkit-bug-importer, webkit.review.bot | ||||||||
Priority: | P1 | Keywords: | InRadar, Regression | ||||||||
Version: | 528+ (Nightly build) | ||||||||||
Hardware: | Mac (Intel) | ||||||||||
OS: | OS X 10.8 | ||||||||||
URL: | http://development.rhubarbproductions.com/webkit/update/ | ||||||||||
Attachments: |
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Description
Kevin M. Dean
2012-10-05 18:22:42 PDT
It pops into compositing layers then stops updating. Created attachment 168848 [details]
Simpler testcase
As you scroll, the positioned children of the overflow div overlap the position:fixed bar, so they become composited (even though they are clipped out, which could be improved). The issue here is related to the fact that we create a compositing layer for the overflow:hidden, but it is marked as not requiring its own backing store. When scrolling, we repaint this layer's m_repaintRect, but that has been computing local to this layer, even though the layer doesn't paint itself. Created attachment 168860 [details]
Patch
Attachment 168860 [details] did not pass style-queue:
Failed to run "['Tools/Scripts/check-webkit-style', '--diff-files', u'Source/WebCore/ChangeLog', u'Source/WebCor..." exit_code: 1
LayoutTests/compositing/repaint/requires-backing-repaint-expected.png:0: Set the svn:mime-type property (svn propset svn:mime-type image/png LayoutTests/compositing/repaint/requires-backing-repaint-expected.png). [image/png] [5]
Total errors found: 1 in 6 files
If any of these errors are false positives, please file a bug against check-webkit-style.
Comment on attachment 168860 [details] Patch Attachment 168860 [details] did not pass chromium-ews (chromium-xvfb): Output: http://queues.webkit.org/results/14392050 New failing tests: compositing/repaint/requires-backing-repaint.html platform/chromium/virtual/softwarecompositing/repaint/requires-backing-repaint.html Created attachment 168981 [details]
Patch
Comment on attachment 168981 [details] Patch http://trac.webkit.org/changeset/131479 Keeping the bug open because there's still an issue with the scrollbar layers not showing up right away. Comment on attachment 168981 [details] Patch Cleared Beth Dakin's review+ from obsolete attachment 168981 [details] so that this bug does not appear in http://webkit.org/pending-commit. |