A "Regular" font will have an empty styleName e.g. "DejaVu Sans,12,-1,5,50,0,0,0,0,0"
so that setBold(true) can work; we deliberately clear the styleName for
"Regular"-like font styles when saving via KConfig, see: writeEntryGui()
from kconfiggroupgui.cpp and https://phabricator.kde.org/D27735 for more
Change nearestExistingFont() to return the same font it's been called on
if the search result gives us the same font (same weight, same style), and
interpret the case when the styleName is empty to mean it's using a
"Regular"-like style if the font weight is QFont::Normal and the styleName
Due to the change to clear font styleName property when saving via
KConfig (D27735), if in kdegloblas you removed the ",Regular|Normal|Book|Roman"
from the end of the *font*= entries, openin the font selection dialog
in the KCM, the very first style is selected, not "Regular" and co. as
it should be. This will be addressed in an upcoming diff.