Fix asynchronous signals from QObjects in different threads

Switches the signal listener in QWebChannel from using
Qt::DirectConnection to Qt::AutoConnection to relay signals
from QObjects in different affinities than the QWebChannel.

Also adds a unit test in testAsyncObject() to verify that
QWebChannel no longer crashes when receiving such a signal,
and that such objects can be added and removed dynamically.

Task-number: QTBUG-51366
Change-Id: I51a4886286fec9257a21ea95360c1ea8889a584a
Reviewed-by: Dave Andrews <jetdog330@hotmail.com>
Reviewed-by: Milian Wolff <milian.wolff@kdab.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/src/webchannel/signalhandler_p.h b/src/webchannel/signalhandler_p.h
index 971c1c9..0f99c5c 100644
--- a/src/webchannel/signalhandler_p.h
+++ b/src/webchannel/signalhandler_p.h
@@ -178,7 +178,7 @@ void SignalHandler<Receiver>::connectTo(const QObject *object, const int signalI
     } // otherwise not yet connected, do so now
 
     static const int memberOffset = QObject::staticMetaObject.methodCount();
-    QMetaObject::Connection connection = QMetaObject::connect(object, signal.methodIndex(), this, memberOffset + signalIndex, Qt::DirectConnection, 0);
+    QMetaObject::Connection connection = QMetaObject::connect(object, signal.methodIndex(), this, memberOffset + signalIndex, Qt::AutoConnection, 0);
     if (!connection) {
         qWarning() << "SignalHandler: QMetaObject::connect returned false. Unable to connect to" << object << signal.name() << signal.methodSignature();
         return;