fix: remove erroneous GSUB substitutions from halt/palt/vhal/vpal (kanji switching to Chinese glyphs)#12
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fix: remove erroneous GSUB substitutions from halt/palt/vhal/vpal (kanji switching to Chinese glyphs)#12halken wants to merge 2 commits into
halken wants to merge 2 commits into
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The `halt` (Alternate Half Widths) and `palt` (Proportional Alternate Widths) features—together with their vertical counterparts `vhal` and `vpal`—were defined as GSUB substitution lookups instead of GPOS metric adjustments. These lookups contained hundreds of ideograph substitutions copied from the traditional-forms (`trad`), JIS78/JIS90 (`jp78`/`jp04`) and vertical (`vert`/`vrt2`) features, including many Japanese shinjitai-to-traditional conversions (e.g. 亜→亞, 医→醫, 円→圓). As a result, enabling `halt`/`palt` for width adjustment in Figma or via CSS `font-feature-settings` unexpectedly switched Japanese kanji to Chinese (traditional) glyph forms. This defect was present from the initial import of the Glyphs source and affects all four weights (Thin/Regular/Bold/ExtraBold). Fix: clear the substitution code from `halt`/`palt`/`vhal`/`vpal` in all four `fontinfo.plist` sources so these features no longer alter glyphs. Glyph-form switching remains available through the dedicated `trad`, `jp78` and `jp04` features, which are left untouched. Verification: - hb-shape: `halt=1`/`palt=1` no longer change kanji glyphs; `trad=1` still converts to traditional forms. - GSUB: halt/palt/vhal/vpal substitution counts are 0 in all weights; trad (309) and jp78 (299) are preserved. - fontspector (googlefonts profile): identical results before and after (PASS 313 / WARN 98 / FAIL 25 / ERROR 4); no new failures introduced. Note: this change only stops the incorrect glyph substitution. Proper half-/proportional-width GPOS metrics for halt/palt are out of scope and can be added separately. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
The build job only uploads the github-pages artifact on the main branch, but the deploy job ran unconditionally. On PR branches the deploy job tried to deploy a non-existent artifact and failed. Add the same main-branch guard to the deploy job so it is skipped on non-main branches. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
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Summary
Enabling
halt(Alternate Half Widths) orpalt(Proportional Alternate Widths) in Figma or via CSSfont-feature-settingsunexpectedly switched some Japanese kanji to Chinese (traditional) glyph forms (e.g. 亜→亞, 医→醫, 円→圓, 辺→邊).Root cause:
halt/palt— and their vertical counterpartsvhal/vpal— were defined as GSUB substitution lookups instead of GPOS metric adjustments.Each contained hundreds of ideograph substitutions copied from the traditional-forms (
trad), JIS78/JIS90 (jp78/jp04) and vertical (vert/vrt2) features, so a feature meant only to adjust glyph width also changed the glyph shape.The defect has existed since the initial import of the Glyphs source and affects all four weights (Thin / Regular / Bold / ExtraBold).
Changes
halt,palt,vhalandvpalin all fourfontinfo.plistsources so these features no longer substitute glyphs.trad,jp78andjp04features.Verification
halt=1/palt=1, kanji glyphs no longer change; withtrad=1, traditional-form conversion still works as expected.trad(309) andjp78(299) are preserved.Notes
halt/paltis out of scope and can be done in a follow-up.gftools buildercachesLINESeedJP/sources/instance_ufos/.Remove that directory (and
build.stamp) before rebuilding, otherwise source changes to feature code may not be reflected in the output fonts.