cutehmi.daemon.3/dev/cutehmi.daemon-1.workaround.Qt.QTBUG-73649.txt

0001 Problem:
0002
0003 Class QQmlApplicationEngine connects Qt.quit() signal to
0004 QCoreApplication::quit() and QQmlApplicationEngine::exit() signal to
0005 QCoreApplication::exit(), but it does so with AutoConnection. This causes in
0006 some circumstances problems, which are described in Qt documentation.
0007
0008 "It's good practice to always connect signals to this slot using a
0009 QueuedConnection. If a signal connected (non-queued) to this slot is emitted
0010 before control enters the main event loop (such as before "int main" calls
0011 exec()), the slot has no effect and the application never exits. Using a queued
0012 connection ensures that the slot will not be invoked until after control enters
0013 the main event loop." -- Qt documentation on QCoreApplication::exit().
0014
0015 Investigation:
0016
0017 File qtdeclarative/src/qml/qml/qqmlapplicationengine.cpp contains method
0018 QQmlApplicationEnginePrivate::init(), which contains following lines.
0019
0020 ```
0021 q->connect(q, SIGNAL(quit()), QCoreApplication::instance(), SLOT(quit()));
0022 q->connect(q, &QQmlApplicationEngine::exit, QCoreApplication::instance(), &QCoreApplication::exit);
0023 ```
0024
0025 Workaround:
0026
0027 Disconnect signals and connect them again with QueuedConnection.
0028