RESOLVED FIXED 204605
Flashing and partly visible elements 
https://bugs.webkit.org/show_bug.cgi?id=204605
Summary Flashing and partly visible elements
Roland Soos
Reported 2019-11-26 01:44:37 PST
Created attachment 384339 [details] Test Elements are flashing or become partly rendered after transform change. Reproduce: 1. Open in Safari on iPad or iPhone: https://smartslider3.com/bugs/webkit/flashing/ 2. Swipe left on the two small image 3. It starts to amimate and the elements are flashing and end up being partly visible. Screen capture: https://www.youtube.com/watch?v=FizN0noXky0 Attached the source code for testing.
Attachments
Test (1.03 MB, application/x-zip-compressed)
2019-11-26 01:44 PST, Roland Soos 		no flags
Details
Reduced test case (1.65 KB, text/html)
2019-12-02 19:24 PST, Simon Fraser (smfr) 		no flags
Details
Testcase which reproduces on trunk (1.66 KB, text/html)
2020-03-24 20:47 PDT, Simon Fraser (smfr) 		no flags
Details
Patch (15.89 KB, patch)
2020-03-25 12:39 PDT, Simon Fraser (smfr) 		zalan: review+
DetailsFormatted DiffDiff
Show Obsolete (1) View All Add attachment proposed patch, testcase, etc.
Radar WebKit Bug Importer
Comment 1 2019-11-26 15:45:15 PST
<rdar://problem/57496061>
Simon Fraser (smfr)
Comment 2 2019-12-02 14:37:43 PST
I can reproduce. Looks like we fail to repaint when the animating photos drop out of layers.
Simon Fraser (smfr)
Comment 3 2019-12-02 19:24:08 PST
Created attachment 384682 [details] Reduced test case This is about repaints in backing sharing layers.
Simon Fraser (smfr)
Comment 4 2019-12-02 22:13:23 PST
We have a layer tree that looks like this: S---------C-c-- -- ------ ------ 0x80945eb00 (0,0) width=858 height=1029 (layerID 40) {sc 5} RenderView S-----------c-- -- ------ ------ + 0x80945ec60 (0,0) width=858 height=544 <html> -NO-------CP--- -- ------ ------ n 0x80945edc0 (18,10) width=822 height=524 (layerID 46) {sc 6} <div> class='container' S----------pcs- -- ------ ------ + 0x80945e000 (12,12) width=2000 height=0 <div> class='wrapper' S-O-------C-cs- -- ------ ------ + 0x80945e160 (0,0) width=2000 height=250 (layerID 47) clipping <div> class='intermediate2' S--A------C--s- -- ------ ------ + 0x80945e2c0 (22,22) width=300 height=200 (layerID 43) <div> class='animated slide' 0x80945e2c0 becomes non-composited, issuing a repaint in 0x80945e160. 0x80945e160 becomes non-composited, which also needs to issue a repaint. It should repaint in 0x80945e000, but when we issue this repaint, we're also in the process of rebuilding backing sharing layers, so 0x80945e000 isn't currently marked as "paints into provided backing" in RenderLayer::enclosingCompositingLayerForRepaint(), so we end up issuing the repaint on the RenderView's layer.
Simon Fraser (smfr)
Comment 5 2020-03-24 19:00:32 PDT
The testcase no longer reproduces this after https://trac.webkit.org/changeset/258336/webkit, and the original testcase seems to have lost its images.
Simon Fraser (smfr)
Comment 6 2020-03-24 20:47:25 PDT
Created attachment 394467 [details] Testcase which reproduces on trunk
Simon Fraser (smfr)
Comment 7 2020-03-24 22:08:41 PDT
*** Bug 207689 has been marked as a duplicate of this bug. ***
Simon Fraser (smfr)
Comment 8 2020-03-24 22:09:39 PDT
*** Bug 209526 has been marked as a duplicate of this bug. ***
Simon Fraser (smfr)
Comment 9 2020-03-25 12:39:36 PDT
Created attachment 394526 [details] Patch
Simon Fraser (smfr)
Comment 10 2020-03-25 15:29:26 PDT
https://trac.webkit.org/changeset/259015/webkit
Simon Fraser (smfr)
Comment 11 2020-05-13 09:57:15 PDT
*** Bug 211841 has been marked as a duplicate of this bug. ***
Note You need to log in before you can comment on or make changes to this bug.