197783 2019-05-10 10:14:57 -0700 Backing sharing should not happen for stacking-order descendants of already-sharing layers 2019-05-11 10:21:22 -0700 1 1 1 Unclassified WebKit Compositing WebKit Nightly Build Unspecified Unspecified RESOLVED DUPLICATE 197692 InRadar P2 Normal --- 197561 1 simon.fraser webkit-unassigned simon.fraser webkit-bug-importer oldest_to_newest 1535052 0 simon.fraser 2019-05-10 10:14:57 -0700 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. 1535053 1 369560 simon.fraser 2019-05-10 10:15:16 -0700 Created attachment 369560 Testcase (shows incorrect opacity rendering) 1535276 2 webkit-bug-importer 2019-05-10 17:41:56 -0700 <rdar://problem/50684464> 1535280 3 simon.fraser 2019-05-10 17:51:18 -0700 This bug leads to incorrect rendering of sharing layers with opacity, and assertions. It's required before bug 197692 can be fixed. 1535356 4 simon.fraser 2019-05-11 10:21:22 -0700 Bug 197692 fixed this *** This bug has been marked as a duplicate of bug 197692 *** 369560 2019-05-10 10:15:16 -0700 2019-05-10 10:15:16 -0700 Testcase (shows incorrect opacity rendering) no-sharing-of-paint-nested-layers.html text/html 936 simon.fraser PCFET0NUWVBFIGh0bWw+IDwhLS0gd2Via2l0LXRlc3QtcnVubmVyIFsgaW50ZXJuYWw6QXN5bmNP dmVyZmxvd1Njcm9sbGluZ0VuYWJsZWQ9dHJ1ZSBdIC0tPgo8aHRtbD4KPGhlYWQ+CiAgICA8dGl0 bGU+VGVzdHMgcGFpbnRpbmcgb2YgYSB0cmFuc2Zvcm1lZCBsYXllciBpbnRvIHNoYXJlZCBiYWNr aW5nPC90aXRsZT4KICAgIDxzdHlsZT4KICAgICAgICAuc2Nyb2xsYWJsZSB7CiAgICAgICAgICAg IG92ZXJmbG93LXk6IHNjcm9sbDsKICAgICAgICAgICAgaGVpZ2h0OiAzMDBweDsKICAgICAgICAg ICAgd2lkdGg6IDMwMHB4OwogICAgICAgICAgICBtYXJnaW46IDEwcHg7CiAgICAgICAgICAgIGJv cmRlcjogMXB4IHNvbGlkIGJsYWNrOwogICAgICAgIH0KCiAgICAgICAgLnNoYXJpbmcgewogICAg ICAgICAgICBwb3NpdGlvbjogcmVsYXRpdmU7CiAgICAgICAgICAgIHRvcDogMzBweDsKICAgICAg ICAgICAgbGVmdDogMzBweDsKICAgICAgICAgICAgd2lkdGg6IDIwMHB4OwogICAgICAgICAgICBo ZWlnaHQ6IDIwMHB4OwogICAgICAgICAgICBiYWNrZ3JvdW5kLWNvbG9yOiBncmVlbjsKICAgICAg ICB9CiAgICAKICAgICAgICAuc3BhY2VyIHsKICAgICAgICAgICAgaGVpZ2h0OiA1MDBweDsKICAg ICAgICB9CiAgICAgICAgCiAgICAgICAgLm91dGVyIHsKICAgICAgICAgICAgb3BhY2l0eTogMC41 OwogICAgICAgIH0KICAgIDwvc3R5bGU+CjwvaGVhZD4KPGJvZHk+CiAgICA8ZGl2IGNsYXNzPSJz Y3JvbGxhYmxlIj4KICAgICAgICA8ZGl2IGNsYXNzPSJvdXRlciBzaGFyaW5nIj4KICAgICAgICAg ICAgPGRpdiBjbGFzcz0ic2hhcmluZyI+CiAgICAgICAgICAgICAgICAKICAgICAgICAgICAgPC9k aXY+CiAgICAgICAgPC9kaXY+CiAgICAgICAgPGRpdiBjbGFzcz0ic3BhY2VyIj48L2Rpdj4KICAg IDwvZGl2Pgo8L2JvZHk+CjwvaHRtbD4K