QNAM hangs if net request is made after going offline

This comes from ubuntu, but effect other platforms, including Linux desktop.

https://bugs.launchpad.net/ubuntu/+source/qtbase-opensource-src/+bug/1470700

If QNAM is created and then device/machine goes offline, request will hang.

If QNAM is created when offline, request will report error. If device goes online, request will succeed. If the device goes offline, the request will not return an error and seem to hang.

Using this code:

QCoreApplication app(argc, argv);
QNetworkAccessManager mgr;

QUrl url(argv[1]);
for (; {
qDebug() << "Starting request" << mgr.networkAccessible();
auto reply = mgr.get(QNetworkRequest(url));
QObject::connect(reply, &QNetworkReply::finished, [&]()

{ qWarning() << "Error state:" << reply->error() << reply->errorString(); printf("%s\n", reply->readAll().constData()); reply->deleteLater(); app.quit(); }

);
app.exec();
qDebug() << "Done. Sleeping 5 seconds";
sleep(5);
}