How/where is font hinting performed in libreoffice?

[Frank Steiner <fsteiner-mail1@xxxxxxxxxxxxxx>]

Hi,

while trying to debug the problem described in
https://bugs.documentfoundation.org/show_bug.cgi?id=157348
further I'd like to understand how font rendering w.r.t. hinting
is done in libreoffice for Linux.

In 7.4.7, Microsoft fonts like Arial are shown with thin lines when
FREETYPE_PROPERTIES="truetype:interpreter-version=35" is set and

<match target="font">
 <edit name="autohint" mode="assign">
  <bool>false</bool>
 <edit>
<match>


is defined for Arial (or in general) in e.g. ~/.config/fontconfig/fonts.conf.
When setting the interpreter-version to 40 or autohint to "true",
Arial and all other Microsoft fonts are way thicker.

In LO 7.5.* and later, all Microsoft fonts are always thick. So either
"truetype:interpreter-version=35" is no longer respected by libreoffice,
or autohinting is always forced regardless of the fontconfig settings.

But from looking at the libreoffice source code, it seems that it
just relies on the settings it finds in fontconfig.

Can someone tell me if the decision about autohinting etc. is done
inside libreoffice at some place?  Or does it fully rely on the
external settings of fontconfig?
Is it possible that libreoffice > 7.4.7. enforces autohinting internally?

And/or could would the missing support for "truetype:interpreter-version=35"
come from inside libreoffice or from an external library that
libreoffice is linked against?

Thanks a lot!
cu,
Frank