Oldstlye numbers 4 inconsistent between proportional and tabular

[alerque]

Originally reported on Linux Libertine here, the 4 glyph shape for +onum changes between +pnum and +tnum:

\begin[papersize=a7]{document}
\nofolios
\neverindent
\begin[family=Libertinus Serif,size=30pt]{font}
\font[features="+pnum"]{0123456789}\hfill\break
\font[features="+tnum"]{0123456789}\hfill\break
\font[features="+tnum,+onum"]{0123456789}\hfill\break
\font[features="+pnum,+onum"]{0123456789}\hfill\break
\end{font}
\end{document}

[Stephen-Leibowitz]

I downloaded Libertinus from fonts.google.com. I then tested it and used this CSS: font-variant-numeric: proportional-nums oldstyle-nums;

I was able to see proportional and old-style with certain other fonts, such as Cambria, for which they were not the OpenType defaults, but not for Libertinus Serif Regular.

I also analyzed Libertinus with https://wakamaifondue.com/beta/ . Again, no proportional or old-style. Here is a summary from wakamaifondue:

Filename - LIBERTINUSSERIF-REGULAR.TTF Filesize - 486 KB Format - TTF Font family - Libertinus Serif Font subfamily - Regular Unique font identifier - 5.000;QUE ;LibertinusSerif-Regular Font name - Libertinus Serif Regular Version string - Version 7.051;RELEASE PostScript name - LibertinusSerif-Regular Manufacturer name - Caleb Maclennan Designer - Philipp H. Poll, Khaled Hosny URL vendor - https://github.com/alerque/libertinus License description - This Font Software is licensed under the SIL Open Font License, Version 1.1. This license is available with a FAQ at: https://openfontlicense.org URL license info - https://openfontlicense.org Layout features cpsp kern mark mkmk