207826 2020-02-15 21:03:42 -0800 An RTL document with scroll snap scrolls to the wrong place on load 2021-07-07 13:28:44 -0700 1 1 1 Unclassified WebKit Scrolling Safari Technology Preview Unspecified Unspecified ASSIGNED https://bugs.webkit.org/show_bug.cgi?id=193671 InRadar P2 Normal --- 214788 1 simon.fraser simon.fraser mrobinson simon.fraser webkit-bug-importer wenson_hsieh oldest_to_newest 1619478 0 390884 simon.fraser 2020-02-15 21:03:42 -0800 Created attachment 390884 Testcase Loading at the testcase on iOS causes the page to scroll all the way to the left, but it should remain scrolled to the right. There are some ordering issues where we fail to compute the non-zero initial snap index in RTL. 1619480 1 simon.fraser 2020-02-15 21:04:42 -0800 The problem is that we push data into the scrolling tree via RenderLayerCompositor::updateScrollingNodeForScrollingRole(), but this runs before updateScrollSnapState() which runs as a post-layout task. 1691165 2 webkit-bug-importer 2020-09-23 10:20:00 -0700 <rdar://problem/69443111> 1775287 3 mrobinson 2021-07-07 09:13:27 -0700 I think this is working now? Perhaps this was improved by recent fixes around treating points as scroll offsets versus scroll positions in ScrollableArea? 1775420 4 simon.fraser 2021-07-07 13:28:44 -0700 I still see issues when first loading the test case on iPhone, with iOS 15. 390884 2020-02-15 21:03:42 -0800 2020-02-15 21:03:42 -0800 Testcase main-frame-snap-rtl.html text/html 1268 simon.fraser CjwhRE9DVFlQRSBodG1sPgoKPGh0bWwgZGlyPSJydGwiPgo8aGVhZD4KICAgIDxzdHlsZT4KICAg ICAgICBib2R5IHsKICAgICAgICAgICAgbWFyZ2luOiAwOwogICAgICAgICAgICBzY3JvbGwtc25h cC10eXBlOiBpbmxpbmU7CiAgICAgICAgfQogICAgICAgIAogICAgICAgIC5jb250YWluZXIgewog ICAgICAgICAgICB3aWR0aDogMjQwMHB4OwogICAgICAgIH0KICAgICAgICAKICAgICAgICAuemVy byB7CiAgICAgICAgICAgIHBvc2l0aW9uOiBhYnNvbHV0ZTsKICAgICAgICAgICAgdG9wOiAwOwog ICAgICAgICAgICBsZWZ0OiAwOwogICAgICAgICAgICB3aWR0aDogMTBweDsKICAgICAgICAgICAg aGVpZ2h0OiAxMHB4OwogICAgICAgICAgICBiYWNrZ3JvdW5kLWNvbG9yOiBvcmFuZ2U7CiAgICAg ICAgfQogICAgICAgIAogICAgICAgCiAgICAgICAgLmNvbnRhaW5lciA+IGRpdiB7CiAgICAgICAg ICAgIG1hcmdpbjogMDsKICAgICAgICAgICAgcGFkZGluZzogMDsKICAgICAgICAgICAgd2lkdGg6 IDQwMHB4OwogICAgICAgICAgICBoZWlnaHQ6IDQwMHB4OwogICAgICAgICAgICBkaXNwbGF5OiBp bmxpbmUtYmxvY2s7CiAgICAgICAgICAgIGZvbnQtc2l6ZTogMjRwdDsKICAgICAgICAgICAgY29s b3I6IHdoaXRlOwogICAgICAgICAgICB0ZXh0LWFsaWduOiBjZW50ZXI7CiAgICAgICAgICAgIHBh ZGRpbmc6IDIwcHg7CiAgICAgICAgICAgIGJveC1zaXppbmc6IGJvcmRlci1ib3g7CiAgICAgICAg ICAgIHNjcm9sbC1zbmFwLWFsaWduOiBzdGFydDsKICAgICAgICB9CiAgICAgICAgCiAgICAgICAg Lm5hcnJvdyB7CiAgICAgICAgICAgIHdpZHRoOiAyMjVweCAhaW1wb3J0YW50OwogICAgICAgIH0K ICAgICAgICAKICAgIDwvc3R5bGU+CjwvaGVhZD4KPGJvZHk+CiAgICA8ZGl2IGNsYXNzPSJjb250 YWluZXIiPgogICAgICAgIDxkaXYgc3R5bGU9J2JhY2tncm91bmQtY29sb3I6IHJlZCc+MTwvZGl2 PjxkaXYgc3R5bGU9J2JhY2tncm91bmQtY29sb3I6IGdyZWVuJz4yPC9kaXY+PGRpdiBzdHlsZT0n YmFja2dyb3VuZC1jb2xvcjogYmx1ZSc+MzwvZGl2PjxkaXYgY2xhc3M9Im5hcnJvdyIgc3R5bGU9 J2JhY2tncm91bmQtY29sb3I6IGFxdWEnPjQ8L2Rpdj48ZGl2IHN0eWxlPSdiYWNrZ3JvdW5kLWNv bG9yOiB5ZWxsb3cnPjU8L2Rpdj48ZGl2IHN0eWxlPSdiYWNrZ3JvdW5kLWNvbG9yOiBmdWNoc2lh Jz42PC9kaXY+CiAgICA8L2Rpdj4KICAgIDxkaXYgY2xhc3M9Inplcm8iPgogICAgPC9kaXY+Cjwv Ym9keT4KPC9odG1sPgo=