I have downloaded a lot of fonts for my Libre, and am wary of an upgrade wiping them all out.
You don’t say what system are running and what version of LibreOffice. Normally only the fonts provided by LibreOffice are stored with some versions of LibreOffice itself. Fonts you yourself download, or provided by other programs are stored in system or private font libraries. LibreOffice scans these libraries and makes them available but they are not part of LibO itself. Unless you have loaded the fonts into a specific LibO font library you should have no problem, I myself have a few hundred of my own. Of course, if you are concerned, make a backup copy first.
On my Ubuntu 12.04 LibreOffice stores its fonts on /opt/libreoffice4.2/share/fonts and /opt/libreoffice4.3/share/fonts (I run at two different versions of LibO ) the system wide fonts are stored in /usr/share/fonts and my specific own 488 additional fonts on /home/peter/.fonts. The library names will vary on other systems. My old Windows system used, if I remember /WINDOWS/Fonts just one bucket for them all, whatever the source.
So, if in doubt make a copy of the font libraries first. Better safe than sorry. … Peter
No, it will not because the fonts are stored in your operating system. LibO access the fonts there.
All your personal setting are stored in the user profile and LibO ensures that they are available in the upgraded installation.