On 7/25/22 14:00, juh+ntg-context--- via ntg-context wrote:
>
> I reported the bug to Mozilla and they answered very fast.
>
> Sadly up too now without a good solution.

Many thanks for the bug report.

> They hint to LuaMetaTex as the cause of the problem. You can follow the
> discussion here.

I would like to compare the LMTX output with the one from LuaTeX.

Sadly, as already reported, LuaTeX doesn’t work on Linux anymore.

> https://bugzilla.mozilla.org/show_bug.cgi?id=1781022

From the two questions from Jonathan Kew, HTML with TeX Gyre Heros is
displayed fine.

I extracted the font from the PDF output document (with a source
document similar to
https://mailman.ntg.nl/pipermail/ntg-context/2022/106302.html) with
"mutools extract", but some info may be missing and Firefox cannot use
it to display the HTML file.

I extracted the font with Fontforge and it was displayed perfectly fine.
But I guess Fontforge is adding some info when generating the OTF font
(font size is bigger: 4KB and 2.3KB when extracted with mutools).

I’m no font expert, but what astonishes me is that it isn’t clear
whether the font has lost the hinting information or not with LMTX
(sorry if I got this wrong).

I have no idea whether Identity-H may be preventing the FreeType
autohinter from working properly. But ft-view (from freetype-demos)
displays poorly the font extracted without FontForge (unlike the font
extracted with it). I attach the first font.

After switching hinting from on to auto, the autohinter displays the
font way better.

To reproduce the issue "ftview  20 font-0009.otf" and press "a".

Just in case it might help,

Pablo