Fix random crashes when bearer suddenly goes down

1. QNetworkSession being deleted from the closed signal caused data
   abort or E32User-CBase 49 panics. (both observed)
2. Potential E32User-CBase 46 panic in
   ConnectionProgressNotifier::StartNotifications()

Reviewed-by: Aaron Tunney
Reviewed-By: Markus Goetz

Task-Number: QTBUG-17196
(cherry picked from commit 8fe811e14b6db6a9637a5bf6d276613786291762)

4 files changed, 13 insertions, 6 deletions

diff --git a/src/network/access/qnetworkaccessmanager.cpp b/src/network/access/qnetworkaccessmanager.cpp
index ea18367..5b518de 100644
--- a/src/network/access/qnetworkaccessmanager.cpp
+++ b/src/network/access/qnetworkaccessmanager.cpp
@@ -1369,10 +1369,11 @@ void QNetworkAccessManagerPrivate::createSession(const QNetworkConfiguration &co
 
     networkSession = QSharedNetworkSessionManager::getSession(config);
 
-    QObject::connect(networkSession.data(), SIGNAL(opened()), q, SIGNAL(networkSessionConnected()));
-    QObject::connect(networkSession.data(), SIGNAL(closed()), q, SLOT(_q_networkSessionClosed()));
+    QObject::connect(networkSession.data(), SIGNAL(opened()), q, SIGNAL(networkSessionConnected()), Qt::QueuedConnection);
+    //QueuedConnection is used to avoid deleting the networkSession inside its closed signal
+    QObject::connect(networkSession.data(), SIGNAL(closed()), q, SLOT(_q_networkSessionClosed()), Qt::QueuedConnection);
     QObject::connect(networkSession.data(), SIGNAL(stateChanged(QNetworkSession::State)),
-                     q, SLOT(_q_networkSessionStateChanged(QNetworkSession::State)));
+                     q, SLOT(_q_networkSessionStateChanged(QNetworkSession::State)), Qt::QueuedConnection);
 
     _q_networkSessionStateChanged(networkSession->state());
 }
diff --git a/src/network/bearer/qnetworksession.cpp b/src/network/bearer/qnetworksession.cpp
index b0b7d3d..9503553 100644
--- a/src/network/bearer/qnetworksession.cpp
+++ b/src/network/bearer/qnetworksession.cpp
@@ -250,6 +250,9 @@ QNetworkSession::QNetworkSession(const QNetworkConfiguration& connectionConfig,
             break;
         }
     }
+
+    qRegisterMetaType<QNetworkSession::State>();
+    qRegisterMetaType<QNetworkSession::SessionError>();
 }
 
 /*!
diff --git a/src/network/bearer/qnetworksession.h b/src/network/bearer/qnetworksession.h
index c51cb4f..0bca4b6 100644
--- a/src/network/bearer/qnetworksession.h
+++ b/src/network/bearer/qnetworksession.h
@@ -139,6 +139,9 @@ private:
     friend class QNetworkSessionPrivate;
     };
 
+Q_DECLARE_METATYPE(QNetworkSession::State);
+Q_DECLARE_METATYPE(QNetworkSession::SessionError);
+
 #ifndef QT_MOBILITY_BEARER
 QT_END_NAMESPACE
 #else
diff --git a/src/plugins/bearer/symbian/qnetworksession_impl.cpp b/src/plugins/bearer/symbian/qnetworksession_impl.cpp
index 433eef6..741f8c5 100644
--- a/src/plugins/bearer/symbian/qnetworksession_impl.cpp
+++ b/src/plugins/bearer/symbian/qnetworksession_impl.cpp
@@ -1552,8 +1552,8 @@ void ConnectionProgressNotifier::StartNotifications()
 {
     if (!IsActive()) {
         SetActive();
+        iConnection.ProgressNotification(iProgress, iStatus);
     }
-    iConnection.ProgressNotification(iProgress, iStatus);
 }
 
 void ConnectionProgressNotifier::StopNotifications()
@@ -1569,10 +1569,10 @@ void ConnectionProgressNotifier::DoCancel()
 void ConnectionProgressNotifier::RunL()
 {
     if (iStatus == KErrNone) {
-        QT_TRYCATCH_LEAVING(iOwner.handleSymbianConnectionStatusChange(iProgress().iStage, iProgress().iError));
-    
         SetActive();
         iConnection.ProgressNotification(iProgress, iStatus);
+        // warning, this object may be deleted in the callback - do nothing after handleSymbianConnectionStatusChange
+        QT_TRYCATCH_LEAVING(iOwner.handleSymbianConnectionStatusChange(iProgress().iStage, iProgress().iError));
     }
 }