Bug 298244 – REGRESSION(299282@main):[ iOS ] imported/w3c/web-platform-tests/css/css-scroll-anchoring/shadow-dom-subscroller.html is a constant failure

• Status: RESOLVED
• Resolution: FIXED
• Component: Page Loading

[Bryan Medina]

imported/w3c/web-platform-tests/css/css-scroll-anchoring/shadow-dom-subscroller.html

is a constant text failure occurring on iOS Debug, and it is a flakey test on iOS Release.

HISTORY:
https://results.webkit.org/?suite=layout-tests&test=imported%2Fw3c%2Fweb-platform-tests%2Fcss%2Fcss-scroll-anchoring%2Fshadow-dom-subscroller.html

TEXT DIFF:
Scrolling over this element doesn't scroll the main scroller


FAIL Ensure there is no scroll anchoring adjustment in the main frame. assert_equals: expected 100 but got 0

TEXT DIFF URL:
https://build.webkit.org/results/Apple-iOS-18-Simulator-Debug-WK2-Tests/299426@main%20(1559)/imported/w3c/web-platform-tests/css/css-scroll-anchoring/shadow-dom-subscroller-actual.txt

[Radar WebKit Bug Importer]

<rdar://problem/159679987>

[Bryan Medina]

I was able to reproduce the text failure locally on my device running iOS 18 Simulator Release ToT using the following command:

run-webkit-tests imported/w3c/web-platform-tests/css/css-scroll-anchoring/shadow-dom-subscroller.html --ios-simulator --iterations=5

[EWS]

Test gardening commit 299442@main (680b12de6022): <https://commits.webkit.org/299442@main>

Reviewed commits have been landed. Closing PR #50185 and removing active labels.

[Bryan Medina]

I was able to find the regression range/point by testing at 299281@main using the reproduction steps mentioned above, where it passed, and started to fail at 299283@main. As of this point, I believe the regression point is somewhere between 299282@main and 299283@main

[Alexey Proskuryakov]

This would make it 299282@main, as 299283 is clearly unrelated. A bit surprising, but that could just indicate a significant bug.

[Basuke Suzuki]

Pull request: https://github.com/WebKit/WebKit/pull/51902

[EWS]

Committed 301215@main (7f2816ca93dd): <https://commits.webkit.org/301215@main>

Reviewed commits have been landed. Closing PR #51902 and removing active labels.