Currently, the original selector text is not overwritten, thus displaying wrong content with CSSOM cssText() https://github.com/WebKit/WebKit/blob/main/LayoutTests/imported/w3c/web-platform-tests/css/css-nesting/cssom-expected.txt#L11
<rdar://problem/108041191>
Pull request: https://github.com/WebKit/WebKit/pull/12738
Committed 262961@main (fdf42acd549d): <https://commits.webkit.org/262961@main> Reviewed commits have been landed. Closing PR #12738 and removing active labels.
Committed 259548.664@safari-7615-branch (250c4928b0b6): <https://commits.webkit.org/259548.664@safari-7615-branch> Reviewed commits have been landed. Closing PR #554 and removing active labels.