Font previews in some apps render incorrectly with lots of extra horizontal space

[somelinguist]

Describe the bug In some font preview apps like PopChar and Font File Browers, versions 7.050 and 7.051 of Libertinus Serif, Libertinus Sans, and Libertinus Serif Display appear with a lot of horizontal space on both sides of each glyph. In PopChar, it causes each glyph to be rendered at a very small size. See the screenshots below of Libertinus Serif Regular compared to other fonts.

Actually using the fonts in other apps and documents to compose text works fine.

Screenshots / logs

Additional context Previous versions still display correctly in both PopChar and Font File Browser. Did anything change in the latest versions that might have affected this?

[alerque]

Congrats on the strangest bug report I've seen this week. I have no idea what this is about.

Nothing in the rage v7.040..v7.050 suggests itself as being problematic. The biggest change likely to be responsible here is tooling: lots of the tools used to build the font have been updated in the intervening years (fontmake, fonttools, psautohint, etc.). Its not impossible there is some error in this font repository triggering this behavior, but it's also possible some font handling library introduced the issue along the way.

Out of curiosity do you have the same results with the newly minted TTF variants, or only the OTFs? Does it affect all fonts in the family or just Libertinus Serif?

[somelinguist]

Congrats on the strangest bug report I've seen this week. I have no idea what this is about.

Thanks! I try!

Thanks for the explanation about the tooling. It's no fun with tooling updates create issues.

I just tried the TTF of Libertinus Serif Regular, and it looks better, but still has roughly the same problem?

[somelinguist]

Sorry I don't know enough about fonts to be much help.

I just found this site https://fontdrop.info that gives lots of info for font files you drop on it.

I happened to have old files for 7.030 on my drive as well, so I compared the Libertinus Serif Regular OTF files for both, and some of width/size values are significantly different:

	7.051	7.030
head – Font Header Table
xMin:	-6275	-1325
yMin:	-256	-256
xMax:	6171	1269
yMax:	1125	928
hhea – Horizontal Header Table
advanceWidthMax	6272	1300
minLeftSideBearing	-6275	-1325
minRightSideBearing	-953	-439
xMaxExtent	6171	1269

Sorry again that I don't know much about how those would be set, etc., or if that might actually be what is affecting previews for me. :)

[somelinguist]

Does it affect all fonts in the family or just Libertinus Serif?

Sorry, I missed this question. It looks like all of them except for Libertinus Mono.