Generic Unix Theme: Don't crash if D-Bus is not running

Change-Id: I215ef25fe943730ba8b1976695a04a4aa86638f1
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>
Reviewed-by: Dmitry Shachnev <mitya57@gmail.com>

1 files changed, 5 insertions, 3 deletions

diff --git a/src/platformsupport/themes/genericunix/qgenericunixthemes.cpp b/src/platformsupport/themes/genericunix/qgenericunixthemes.cpp
index 323e8fd13b..4e7421e98f 100644
--- a/src/platformsupport/themes/genericunix/qgenericunixthemes.cpp
+++ b/src/platformsupport/themes/genericunix/qgenericunixthemes.cpp
@@ -120,9 +120,11 @@ static bool isDBusTrayAvailable() {
 #ifndef QT_NO_DBUS
 static bool checkDBusGlobalMenuAvailable()
 {
-    QDBusConnection connection = QDBusConnection::sessionBus();
-    QString registrarService = QStringLiteral("com.canonical.AppMenu.Registrar");
-    return connection.interface()->isServiceRegistered(registrarService);
+    const QDBusConnection connection = QDBusConnection::sessionBus();
+    static const QString registrarService = QStringLiteral("com.canonical.AppMenu.Registrar");
+    if (const auto iface = connection.interface())
+        return iface->isServiceRegistered(registrarService);
+    return false;
 }
 
 static bool isDBusGlobalMenuAvailable()