missing quotation marks in \fontname with harfbuzz

[Udi-Fogiel]

run with luahbtex

\input luaotfload.sty

\font\foo="name:TeX Gyre Termes:mode=harf"\relax
\fontname\foo

\font\foo="name:TeX Gyre Termes"\relax
\fontname\foo

\bye

This is causing problems in LaTeX as the kernel assume \fontname can be
fed up to \font back again, and since the font name has spaces and \fontname
does not have any protection (no braces, nor quotation marks) this
leads to errors. See https://tex.stackexchange.com/questions/721772/conflict-between-setmainfont-and-mainmatter.

[Udi-Fogiel]

BTW, if the quotation marks or braces are just for escaping spaces, wouldn't removing them and the spaces will be easier?

[u-fischer]

I guess that is a similar problem to latex3/fontspec#486

[zauguin]

Fixed in dev with 80c94d6, but the underlying issue is that patch_font callbacks do not run for harf fonts. I'm wondering if that might have other effects too. It's probably not safe to chsnge though since these fonts do look very different and aren't very patchable.