ASSERT failure in void __cdecl QtFontFamily::ensurePopulated(void) on system registed font

Since 5.15.4, font names are trimmed in qfontdatabase.cpp

In my system I've a font that is registered with a space at the end.

I probably can't and never did use it but still, it makes Qt 5.15.4+ applications crash on first font fallback lookup.

I would suggest to simply not populate such fonts in populateFontFamilies.