[legacy-v2/woff] LatinModern NonUnicode causes CSS height problem in Microsoft Word in Firefox

[tomty89]

Issue Summary

Having LatinModernMathJax_NonUnicode-Regular.woff in system causes lines in document opened in Editing mode in Microsoft Word (the online web app) in Firefox to have huge CSS (line-)heights. The problem is not observed in Chromium, so I cannot rule out that it is due to a flaw/bug in Firefox. However, other woff fonts in MathJax2 do not seem to cause the problem. Neither do I know whether Chromium cares about woff in system at all.

With the Arch Linux package mathjax2 remain installed, once /usr/share/fonts/mathjax2/HTML-CSS/Latin-Modern/woff/LatinModernMathJax_NonUnicode-Regular.woff is removed, the problem is gone.

Also see Steps to Reproduce.

Steps to Reproduce:

(0. Remove the mathjax2 package / fonts installed with pacman -R mathjax2)

1. Place mathjax2/HTML-CSS/Latin-Modern/woff/LatinModernMathJax_NonUnicode-Regular.woff under /usr/share/fonts/
2. Start Firefox and open any document with Microsoft Word (online web app); better use private browsing as cache seems to hide the problem sometimes

Technical details:

• MathJax Version: 2.7.9
• Client OS: Arch Linux
• Browser: Firefox 98.0

Supporting information:

Abnormal:

Normal:

[pkra]

This sounds like either a Microsoft Word Web app or Firefox bug. Why file it here?

[tomty89]

Well, as I said, only one particular font file triggers the issue, which seems to indicate it has something to do with the font. (With that said, I planned to also file one on the Firefox side anyway.)

[dpvc]

There could well be an issue with the font file, though I'm not able to find one. The font does seem to have large ascent and descent values, which could account for the issue you are seeing, but so do the other latin-modern fonts, so I'm not sure why that one file would produce the issue while others wouldn't. It does seem like a peculiar bug.

We are in the process of making a font update for MathJax v3, and it will have new versions of the font files, so perhaps it will be a moot point soon.