Font style names are quite irregular and the simplistic matching
implemented in QFontDatabase::styleString(const QFont &) is unable to
properly resolve the style name when font is recreated from a string.
This causes the fonts before and after serialization to be considered
different, even though they are not. The from/toString methods were
made to write and respect the exact font style.
[ChangeLog][QtGui][Important Behavior Changes] QFont::toString() and
QFont::key() were modified to save the font's style name if one is
set, invalidating any stored font identifiers. QFont::fromString()
was also adjusted to accommodate the change.
Task-number: QTBUG-54936
Change-Id: Ibc7c54119acdd8f0950d6049cc89f859bf981504
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@qt.io>
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@theqtcompany.com>
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