283140 2024-11-14 15:19:31 -0800 Switching light/dark modes doesn't update the base background color if the root has `color` set explicitly 2024-11-19 19:20:58 -0800 1 1 1 Unclassified WebKit CSS WebKit Nightly Build Unspecified Unspecified RESOLVED FIXED https://bugs.webkit.org/show_bug.cgi?id=267252 InRadar P2 Normal --- 1 simon.fraser simon.fraser akeerthi koivisto simon.fraser webkit-bug-importer oldest_to_newest 2075207 0 473231 simon.fraser 2024-11-14 15:19:31 -0800 Created attachment 473231 Test case Load the attached test file in MiniBrowser. Switch between light and dark modes either via Web Inspector, or by changing system settings; the page background color should update, but does not. For some reason, the bug does not reproduce in Safari. 2075208 1 simon.fraser 2024-11-14 15:22:36 -0800 The issue here is that the base background color, which is set via `LocalFrameView::updateBackgroundRecursively()`, isn't really represented in the render tree, so there's no render that sees the style change and knows to trigger `updateBackgroundRecursively`. `RenderBox::styleDidChange()` does call `frameView().recalculateBaseBackgroundColor()` when it sees a style change for the document element or body renderers, but on light/dark mode switches, that is triggered by chance because the `color` property (which is inherited) changes, and we get a RepaintForText diff. If the content sets an explicit color on the root, as the test case does, then the bug occurs. 2075224 2 webkit-bug-importer 2024-11-14 15:53:53 -0800 <rdar://problem/139917332> 2075246 3 simon.fraser 2024-11-14 16:53:31 -0800 Pull request: https://github.com/WebKit/WebKit/pull/36673 2076307 4 ews-feeder 2024-11-19 19:20:56 -0800 Committed 286833@main (060793dcd586): <https://commits.webkit.org/286833@main> Reviewed commits have been landed. Closing PR #36673 and removing active labels. 473231 2024-11-14 15:19:31 -0800 2024-11-14 15:19:31 -0800 Test case light-dark-switch-with-root-color.html text/html 295 simon.fraser PCFET0NUWVBFIGh0bWw+CjxodG1sPgo8aGVhZD4KICAgIDxzdHlsZT4KICAgICAgICA6cm9vdCB7 CiAgICAgICAgICBjb2xvci1zY2hlbWU6IGxpZ2h0IGRhcms7CiAgICAgICAgICBjb2xvcjogYmx1 ZTsKICAgICAgICB9CiAgICA8L3N0eWxlPgo8L2hlYWQ+Cjxib2R5PgogICAgPHA+VXNlIHdlYiBp bnNwZWN0b3Igb3Igc3lzdGVtIHNldHRpbmdzIHRvIHN3aXRjaCBiZXR3ZWVuIGxpZ2h0IGFuZCBk YXJrIG1vZGVzLiBUaGUgYmFja2dyb3VuZCBjb2xvciBzaG91bGQgdXBkYXRlLjwvcD4KPC9ib2R5 Pgo8L2h0bWw+Cg==