After having done a few package updates with yum and doing a restart the default system font under both Gnome and KDE have becomes extremely small. On some applications like Firefox and Thunderbird it's so small that the apps become very difficult to handle. Setting font sizes in application settings only affect certain contents (in Firefox the displayed HTML contents, in Thunderbird the e-mail contents), but not the fonts in the menus and dialogs.

The affected PC runs as a server and a few updates have been done before a restart has been done, so it's difficult to tell what update caused this annoying effect.

I guess it has something to do with either X.org or some default font package. Setting/disabling the font dpi (96 dpi) in one of the X configuration files didn't change the situation.

Has anyone run into something similar lately on a Fedora box?

Thnak & Regards,
CSIG

Did some further tweaking to find a solution. It seems that font in menus and dialogs are displayed with an unusual large linefeed value (vertical distance between baselines of subsequent textlines). This becomes very visible in applications that display foe example single-digit number in a square box - the number formerly filled the box neatly, but now it became smaller and being offset to the top area of the box.

It's like having a character glyph placed in a font em-size box that is too large for it.

Still not sure what causes this. All installed fonts are affected, so it's not caused by changes to any single font file.