320744 2026-07-31 08:42:21 -0700 font-* properties should use the metrics of the parent element's font for font-relative unit resolution 2026-08-12 12:55:16 -0700 1 1 1 Unclassified WebKit CSS Safari 18 Unspecified Unspecified RESOLVED FIXED InRadar P2 Normal --- 1 sam sam koivisto webkit-bug-importer oldest_to_newest 2236027 0 sam 2026-07-31 08:42:21 -0700 Currently, we only special case font-size to use the parent elements font metrics for font-relative units, but the CSS Values spec says all properties of the form font-* should use the parent element. In practice, this doesn't really come up, since no other font-* property allows lengths, but through the use of calc() it can still be observed. For example, ``` <style> #container { font-size: 10px; } #element { font-size: 100px; font-size-adjust: calc(1em / 1px); } </style> <div id=container> <div id=element> </div> </div> ``` The computed style for element's font-size-adjust property should be `10` (because it should use the parent font-size where 1em == 10px, and therefore 10px / 1px == 1), and not `100` as it is today. 2236029 1 480895 sam 2026-07-31 08:45:46 -0700 Created attachment 480895 Test case 2238315 2 webkit-bug-importer 2026-08-07 08:43:12 -0700 <rdar://problem/184336424> 2239627 3 sam 2026-08-12 08:24:23 -0700 Pull request: https://github.com/WebKit/WebKit/pull/71441 2239704 4 ews-feeder 2026-08-12 12:55:13 -0700 Committed 319052@main (c64b47e33694): <https://commits.webkit.org/319052@main> Reviewed commits have been landed. Closing PR #71441 and removing active labels. 480895 2026-07-31 08:45:46 -0700 2026-07-31 08:45:46 -0700 Test case test-font-relative-in-font-star.html text/html 563 sam PCFET0NUWVBFIGh0bWw+CjxodG1sPgo8aGVhZD4KICA8c3R5bGU+CgogICAgI2NvbnRhaW5lciB7 CiAgICAgIGZvbnQtc2l6ZTogMTBweDsKICAgIH0KICAgICNlbGVtZW50IHsKICAgICAgZm9udC1z aXplOiAxMDBweDsKICAgICAgZm9udC1zaXplLWFkanVzdDogY2FsYygxZW0gLyAxcHgpOwogICAg fQogIDwvc3R5bGU+CjwvaGVhZD4KPGJvZHk+CjxwcmUgaWQ9Y29uc29sZT48L3ByZT4KCjxkaXYg aWQ9ImNvbnRhaW5lciI+CiAgPGRpdiBpZD0iZWxlbWVudCI+PC9kaXY+CjwvZGl2PgoKPHNjcmlw dD4KICBjb25zdCBjb25zb2xlID0gZG9jdW1lbnQuZ2V0RWxlbWVudEJ5SWQoImNvbnNvbGUiKTsK CiAgZnVuY3Rpb24gbG9nKG1zZykKICB7CiAgICBjb25zb2xlLnRleHRDb250ZW50ICs9IG1zZyAr ICJcbiI7CiAgfQogIAogIGxvZygiZm9udC1zaXplLWFkanVzdCIpCiAgbG9nKCJjb21wdXRlZDog IiArIHdpbmRvdy5nZXRDb21wdXRlZFN0eWxlKGRvY3VtZW50LmdldEVsZW1lbnRCeUlkKCJlbGVt ZW50IikpLmZvbnRTaXplQWRqdXN0KTsKPC9zY3JpcHQ+CjwvYm9keT4KPC9odG1sPgo=