Bug 197783 - Backing sharing should not happen for stacking-order descendants of already-sharing layers
Summary: Backing sharing should not happen for stacking-order descendants of already-s...
Status: RESOLVED DUPLICATE of bug 197692
Alias: None
Product: WebKit
Classification: Unclassified
Component: Compositing (show other bugs)
Version: WebKit Nightly Build
Hardware: Unspecified Unspecified
: P2 Normal
Assignee: Nobody
Keywords: InRadar
Depends on:
Blocks: 197561
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Reported: 2019-05-10 10:14 PDT by Simon Fraser (smfr)
Modified: 2019-05-11 10:21 PDT (History)
2 users (show)

See Also:

Testcase (shows incorrect opacity rendering) (936 bytes, text/html)
2019-05-10 10:15 PDT, Simon Fraser (smfr)
no flags Details

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Description Simon Fraser (smfr) 2019-05-10 10:14:57 PDT
We should never do this:

S--------C-c- -- ------ ------ 0x3a6878560 (0,0) width=600 height=588 (layerID 241) {sc 28} RenderView
S----------c- -- ------ ------   + 0x3a68786b8 (0,0) width=600 height=322  <html>
-NO------CP-- -- ------ ------     n 0x3a6878810 (18,10) width=302 height=302 (layerID 246) {sc 29}  <div> class='scrollable'
S--A------p-s -- ------ ------     + 0x3a6878968 (31,31) width=200 height=200  <div> class='outer sharing'
----------p-s -- ------ ------       + 0x3a6878ac0 (30,30) width=200 height=200  <div> class='sharing'

0x3a6878968 is already sharing, so 0x3a6878ac0 should just paint into it, rather than also sharing.

This is causing assertions when trying to get painting with transforms working. We need to behave more like 0x3a6878968 was compositing.
Comment 1 Simon Fraser (smfr) 2019-05-10 10:15:16 PDT
Created attachment 369560 [details]
Testcase (shows incorrect opacity rendering)
Comment 2 Radar WebKit Bug Importer 2019-05-10 17:41:56 PDT
Comment 3 Simon Fraser (smfr) 2019-05-10 17:51:18 PDT
This bug leads to incorrect rendering of sharing layers with opacity, and assertions. It's required before bug 197692 can be fixed.
Comment 4 Simon Fraser (smfr) 2019-05-11 10:21:22 PDT
Bug 197692 fixed this

*** This bug has been marked as a duplicate of bug 197692 ***