QGuiApplication: drop mutex before emitting fontChanged()

Emitting a signal executes an unknowable amount of code. We shouldn't
hold a mutex while doing so. E.g., if the signal emission causes
another call to QGuiApplication::setFont(), the old code would
deadlock, since applicationFontMutex is not recursive.

Fix by taking a copy of the application font under mutex protection,
then dropping the lock for the emission of the signal.

Change-Id: Ib2569b3a08af6ef5f38459a19f74cb0db27b7772
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
Reviewed-by: Lars Knoll <lars.knoll@qt.io>
This commit is contained in:
Marc Mutz 2019-08-23 09:35:20 +02:00
parent b1db1dd655
commit 96ff6e8ebe

View File

@ -3284,8 +3284,11 @@ void QGuiApplication::setFont(const QFont &font)
*QGuiApplicationPrivate::app_font = font;
applicationResourceFlags |= ApplicationFontExplicitlySet;
if (emitChange && qGuiApp)
emit qGuiApp->fontChanged(*QGuiApplicationPrivate::app_font);
if (emitChange && qGuiApp) {
auto font = *QGuiApplicationPrivate::app_font;
locker.unlock();
emit qGuiApp->fontChanged(font);
}
}
/*!