From 7cb2d467c3421eced44ae7b887b8738cc68595fc Mon Sep 17 00:00:00 2001
From: Dave Andrews <jetdog330@hotmail.com>
Date: Mon, 22 Aug 2016 22:43:55 -0400
Subject: 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>
---
 src/webchannel/signalhandler_p.h         |  2 +-
 tests/auto/webchannel/tst_webchannel.cpp | 40 ++++++++++++++++++++++++++++----
 tests/auto/webchannel/tst_webchannel.h   |  2 ++
 3 files changed, 39 insertions(+), 5 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;
diff --git a/tests/auto/webchannel/tst_webchannel.cpp b/tests/auto/webchannel/tst_webchannel.cpp
index 55723ea..2ab820b 100644
--- a/tests/auto/webchannel/tst_webchannel.cpp
+++ b/tests/auto/webchannel/tst_webchannel.cpp
@@ -374,6 +374,12 @@ void TestWebChannel::testInfoForObject()
             method.append(obj.metaObject()->indexOfMethod("setProp(QString)"));
             expected.append(method);
         }
+        {
+            QJsonArray method;
+            method.append(QStringLiteral("fire"));
+            method.append(obj.metaObject()->indexOfMethod("fire()"));
+            expected.append(method);
+        }
         {
             QJsonArray method;
             method.append(QStringLiteral("method1"));
@@ -403,6 +409,12 @@ void TestWebChannel::testInfoForObject()
             signal.append(obj.metaObject()->indexOfMethod("sig2(QString)"));
             expected.append(signal);
         }
+        {
+            QJsonArray signal;
+            signal.append(QStringLiteral("replay"));
+            signal.append(obj.metaObject()->indexOfMethod("replay()"));
+            expected.append(signal);
+        }
         QCOMPARE(info["signals"].toArray(), expected);
     }
 
@@ -735,10 +747,30 @@ void TestWebChannel::testAsyncObject()
     int method = obj.metaObject()->indexOfMethod("setProp(QString)");
     QVERIFY(method != -1);
 
-    QSignalSpy spy(&obj, &TestObject::propChanged);
-    channel.d_func()->publisher->invokeMethod(&obj, method, args);
-    QVERIFY(spy.wait());
-    QCOMPARE(spy.at(0).at(0).toString(), args.at(0).toString());
+    {
+        QSignalSpy spy(&obj, &TestObject::propChanged);
+        channel.d_func()->publisher->invokeMethod(&obj, method, args);
+        QVERIFY(spy.wait());
+        QCOMPARE(spy.at(0).at(0).toString(), args.at(0).toString());
+    }
+
+    channel.registerObject("myObj", &obj);
+    channel.d_func()->publisher->initializeClient(m_dummyTransport);
+
+    QJsonObject connectMessage;
+    connectMessage["type"] = 7;
+    connectMessage["object"] = "myObj";
+    connectMessage["signal"] = obj.metaObject()->indexOfSignal("replay()");
+    channel.d_func()->publisher->handleMessage(connectMessage, m_dummyTransport);
+
+    {
+        QSignalSpy spy(&obj, &TestObject::replay);
+        QMetaObject::invokeMethod(&obj, "fire");
+        QVERIFY(spy.wait());
+        channel.deregisterObject(&obj);
+        QMetaObject::invokeMethod(&obj, "fire");
+        QVERIFY(spy.wait());
+    }
 
     thread.quit();
     thread.wait();
diff --git a/tests/auto/webchannel/tst_webchannel.h b/tests/auto/webchannel/tst_webchannel.h
index 70a368c..94dccf5 100644
--- a/tests/auto/webchannel/tst_webchannel.h
+++ b/tests/auto/webchannel/tst_webchannel.h
@@ -123,6 +123,7 @@ signals:
     void objectPropertyChanged();
     void returnedObjectChanged();
     void propChanged(const QString&);
+    void replay();
 
 public slots:
     void slot1() {}
@@ -141,6 +142,7 @@ public slots:
     }
 
     void setProp(const QString&prop) {emit propChanged(mProp=prop);}
+    void fire() {emit replay();}
 
 protected slots:
     void slot3() {}
-- 
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