151471 2015-11-19 18:13:31 -0800 font-variant-position does not work if the font does not support font features 2025-02-13 23:55:50 -0800 1 1 1 Unclassified WebKit Text WebKit Nightly Build Unspecified Unspecified NEW InRadar P2 Normal --- 149779 1 mmaxfield webkit-unassigned jdaggett jonlee mmaxfield phiw2 rich webkit-bug-importer oldest_to_newest 1143529 0 mmaxfield 2015-11-19 18:13:31 -0800 We need to implement synthesis in this case. 1145750 1 webkit-bug-importer 2015-12-02 15:05:22 -0800 <rdar://problem/23732338> 1149181 2 jdaggett 2015-12-14 19:48:40 -0800 gecko bug for this: https://bugzilla.mozilla.org/show_bug.cgi?id=1024804 reftests (see subsuper*): http://hg.mozilla.org/mozilla-central/file/tip/layout/reftests/font-features 2045523 3 rich 2024-07-10 04:37:47 -0700 If all the characters within the element to be superscripted are available in the webfont then these should be used (this works). However if other characters are present within the sup element, then the entire string should be synthesized. As per the CSS Fonts Module Level 4 spec: Because of the semantic nature of subscripts and superscripts, when the value [of font-variant-position] is either sub or super for a given contiguous run of text, if a variant glyph is not available for all the characters in the run, simulated glyphs should be synthesized for all characters using reduced forms of the glyphs that would be used without this feature applied. This is now implemented correctly in Firefox. Test page: https://clagnut.com/sandbox/subsup.html 2094718 4 rich 2025-02-13 23:55:50 -0800 I see this bug didn't make it into Interop again. Any chance it could be prioritised nonetheless? The bug is harmful in that it removes important visual semantics implied by superscripts and subscripts.