Bug#861304: firefox-esr: Resolved a font problem

[Vlastimil Zíma]

Package: firefox-esr
Followup-For: Bug #861304

Hi Vincas,

I experienced a similar issue with my firefox after upgrade 45.9 to
52.2. Some fonts, namely Helvetica, looked weird and clearly lacked
support of Czech language. I've traced to problem back to fontconfig.

I resolved the issue by upgrading the fontconfig packages to stable
version and running dpkg-reconfigure fontconfig-config as recommended
by https://wiki.debian.org/Fonts. Restart of firefox, or other
affected program, is required. Also the broken link in /etc/fonts/conf.d
was fixed.

The change of fonts can be observed using fc-match. Before the fix it
returned

$ fc-match Helvetica
helvR12-ISO8859-1.pcf.gz: "Helvetica" "Regular"

Note especially the ISO8859-1 encoding. After the reconfigure

$ fc-match Helvetica
texgyreheros-regular.otf: "TeX Gyre Heros" "Regular"

Not it looks fine. Hope this helps.
Vlastik