Babel defined fonts do not work with realscripts package

[dcpurton]

For fonts defined using \babelfont, the realscripts package has no effect unless the the Harfbuzz renderer is selected.

This does not happen for fonts defined directly using fontspec.

I'm not sure whether the fault lies with babel or realscripts as using \addfontfeatures{VerticalPosition=Superior} works as expected.

I might be wrong, but I feel like this used to work with babel.

% TeX Program = lualatex

\documentclass{article}

\usepackage[english]{babel}
\babelfont{rm}{Noto Serif}
\babelfont{sf}[Renderer=Harfbuzz]{Noto Sans}
\usepackage{realscripts}

\newfontfamily\nonbabelnotoserif{Noto Serif}[Renderer=Node]

\begin{document}

\textsuperscript{1234567890} ¹²³⁴⁵⁶⁷⁸⁹⁰ {\addfontfeatures{VerticalPosition=Superior}1234567890}

\sffamily

\textsuperscript{1234567890} ¹²³⁴⁵⁶⁷⁸⁹⁰

\nonbabelnotoserif

\textsuperscript{1234567890} ¹²³⁴⁵⁶⁷⁸⁹⁰

\end{document}

[jbezos]

You are right - it used to work. It works with \babelfont{rm}[Language=Default]{Noto Serif}. I have to see what’s changed.

[jbezos]

Actually, it's an issue you’ve encountered before, although in a different context. realscripts relies on \fontspec_if_feature:nTF, which fails to properly fall back to the default font feature if the language system is set, even if the feature actually works. It worked formerly because luaotfload/fontspec behaved in a different way. See latex3/fontspec#558 (comment). Here is an example without babel:

\documentclass{article}

\usepackage{fontspec}
\setmainfont[Language=English]{Noto Serif}
\setsansfont{Noto Serif}
\usepackage{realscripts}

\begin{document}

\fontname\font

X\textsuperscript{1234567890} ¹²³⁴⁵⁶⁷⁸⁹⁰ {\addfontfeatures{VerticalPosition=Superior}1234567890}

\sffamily

\fontname\font

X\textsuperscript{1234567890} ¹²³⁴⁵⁶⁷⁸⁹⁰

\end{document}

[dcpurton]

Thanks @jbezos . Hopefully this will be fixed on the fontspec side sooner rather than later so I stop reporting bugs relating to it 😆