.
From the diff here: https://build.webkit.org/results/Apple-iOS-17-Simulator-Debug-WK2-Tests/277233@main%20(1462)/fast/writing-mode/english-bt-text-with-spelling-marker-diffs.html ...it looks like after 277233@main, there's a tiny difference between the reference and test images.
Created attachment 470839 [details] Image result before 277233@main
Attached an image showing the results (both reference and test) before my fix — there are no spelling dots at all. My change in 277233@main basically made the test start working as intended on iOS 17 (i.e. showing spelling dots). I think we just need to adjust the fuzziness to accommodate.
Pull request: https://github.com/WebKit/WebKit/pull/27029
Committed 277254@main (ef7c999e5c10): <https://commits.webkit.org/277254@main> Reviewed commits have been landed. Closing PR #27029 and removing active labels.
<rdar://problem/126146299>