Created attachment 457307 [details] Actual Description: fast/block/positioning/fixed-container-with-relative-parent.html The first image failure that I see this on the dashboard was 03/29/22 at r292045, but I was not able to find a commit that seemed relevant that would have caused this. REPRODUCTION STEPS I can reproduce this on r292043, but unable to reproduce on r292042. Command: run-webkit-tests --root --exit-after-n-failures 1 --exit-after-n-crashes-or-timeouts 1 --iterations 50 fast/block/positioning/fixed-container-with-relative-parent.html Result: [10/50] fast/block/positioning/fixed-container-with-relative-parent.html failed unexpectedly (reference mismatch maxDifference=255; totalPixels=1240) Exiting early after 2 failures. 10 tests run. 8 tests ran as expected, 2 didn't (40 didn't run): History: https://results.webkit.org/?suite=layout-tests&test=fast%2Fblock%2Fpositioning%2Ffixed-container-with-relative-parent.html&platform=mac&limit=49920&version_name=Big%20Sur&version_name=Monterey Link to image diff: https://build.webkit.org/results/Apple-BigSur-Debug-AppleSilicon-WK2-Tests/r292729%20(5534)/fast/block/positioning/fixed-container-with-relative-parent-diffs.html
Created attachment 457308 [details] Expected
<rdar://problem/91603539>
Marked expecrtation here while the issue is investigated. r292777
Created attachment 457506 [details] Patch
Created attachment 457530 [details] Patch
Created attachment 457535 [details] Patch
Comment on attachment 457535 [details] Patch View in context: https://bugs.webkit.org/attachment.cgi?id=457535&action=review > Source/WebCore/rendering/RenderBlock.cpp:180 > + for (auto it = descendants->begin(); it != descendants->end(); ++it) { Does ListHashSet not support for (auto thing : *descendants)?
Comment on attachment 457535 [details] Patch View in context: https://bugs.webkit.org/attachment.cgi?id=457535&action=review >> Source/WebCore/rendering/RenderBlock.cpp:180 >> + for (auto it = descendants->begin(); it != descendants->end(); ++it) { > > Does ListHashSet not support for (auto thing : *descendants)? It does have support for range loop, but in this case "it" is used at "descendants->insertBefore(it..."
Committed r292817 (249597@main): <https://commits.webkit.org/249597@main> All reviewed patches have been landed. Closing bug and clearing flags on attachment 457535 [details].
Re-opened since this is blocked by bug 239305
Created attachment 457583 [details] Patch
Committed r292855 (249626@main): <https://commits.webkit.org/249626@main> All reviewed patches have been landed. Closing bug and clearing flags on attachment 457583 [details].