311942 2026-04-10 09:47:59 -0700 [Grid] Crash under GridTrackSizingAlgorithm::copyUsedTrackSizesForSubgrid when paint containment changes on subgrid 2026-04-10 16:47:06 -0700 1 1 1 Unclassified WebKit Layout and Rendering WebKit Nightly Build Unspecified Unspecified RESOLVED FIXED https://github.com/web-platform-tests/wpt/pull/59106 InRadar P2 Normal --- 1 sgill26 sgill26 bfulgham simon.fraser webkit-bug-importer zalan oldest_to_newest 2198836 0 478996 sgill26 2026-04-10 09:47:59 -0700 Created attachment 478996 Testcase The following test case triggers a RELEASE_ASSERT in GridTrackSizingAlgorithm::copyUsedTrackSizesForSubgrid. 2198837 1 sgill26 2026-04-10 09:48:22 -0700 rdar://172724120 2198846 2 sgill26 2026-04-10 10:00:40 -0700 Pull request: https://github.com/WebKit/WebKit/pull/62421 2198872 3 sgill26 2026-04-10 10:52:55 -0700 Submitted web-platform-tests pull request: https://github.com/web-platform-tests/wpt/pull/59106 2199015 4 ews-feeder 2026-04-10 16:47:03 -0700 Committed 310968@main (2cc90f478c7e): <https://commits.webkit.org/310968@main> Reviewed commits have been landed. Closing PR #62421 and removing active labels. 478996 2026-04-10 09:47:59 -0700 2026-04-10 09:47:59 -0700 Testcase subgrid-paint-containment-change-crash.html text/html 437 sgill26 PGh0bWw+Cjxib2R5Pgo8ZGl2IHN0eWxlPSJkaXNwbGF5OiBncmlkIj4KICA8ZGl2IGlkPSJjaGFu Z2UiIHN0eWxlPSJkaXNwbGF5OiBncmlkOyBncmlkLXRlbXBsYXRlLXJvd3M6IHN1YmdyaWQgW2Fd IFtiXSBbY107Ij4KICAgIDxkaXY+b25lPC9kaXY+CiAgICA8Zm9vIHN0eWxlPSJkaXNwbGF5OiBn cmlkOyBncmlkLXRlbXBsYXRlLXJvd3M6IHN1YmdyaWQgW2FdIFtiXSBbY107Ij4KICAgICAgPGJh ciBpZD0ieCI+dHdvPC9iYXI+CiAgICA8L2Zvbz4KICA8L2Rpdj4KPC9kaXY+CjwvYm9keT4KPHNj cmlwdD4KICBkb2N1bWVudC5ib2R5Lm9mZnNldEhlaWdodDsKICB4LnN0eWxlLmJvcmRlciA9ICIx cHggc29saWQgcmVkIjsKICBkb2N1bWVudC5nZXRFbGVtZW50QnlJZCgiY2hhbmdlIikuc3R5bGUu Y29udGFpbiA9ICdwYWludCc7Cjwvc2NyaXB0Pgo8L2h0bWw+Cgo=