macOS: delay initialization of small font

During construction of a QStyle, QApplication might not yet be
initialized, e.g. when calling QApplication::setStyle("macOS") before
constructing QApplication. In that case, we cannot access the platform
theme.

We don't just want to skip initializing the small font either though.
Store the smallSystemFont as a std::optional so that we can initialize
it once, when the first widget gets polished.

As a drive-by, remove the unused miniSystemFont variable.

Fixes: QTBUG-108047
Pick-to: 6.4 6.2
Change-Id: Id750770a563611fdbc6c7031fe102a99ea692be7
Reviewed-by: Samuel Gaist <samuel.gaist@idiap.ch>

1 files changed, 1 insertions, 2 deletions

diff --git a/src/plugins/styles/mac/qmacstyle_mac_p_p.h b/src/plugins/styles/mac/qmacstyle_mac_p_p.h
index 8dc8d659e7..e3f1e39d19 100644
--- a/src/plugins/styles/mac/qmacstyle_mac_p_p.h
+++ b/src/plugins/styles/mac/qmacstyle_mac_p_p.h
@@ -262,8 +262,7 @@ public:
     mutable QHash<CocoaControl, NSView *> cocoaControls;
     mutable QHash<CocoaControl, NSCell *> cocoaCells;
 
-    QFont smallSystemFont;
-    QFont miniSystemFont;
+    std::optional<QFont> smallSystemFont;
 
     QMacKeyValueObserver appearanceObserver;
 };