winrt: process pending data before closing a socket connection

If data is received and the remote immediately closes the connection,
it was possible that data was lost. If a remote closes the connection
make sure that any pending data is processed, before signaling closing
of the socket.

Change-Id: Ia94a616a31184fd28695919baaff99811fe0f1dd
Reviewed-by: Andre de la Rocha <andre.rocha@qt.io>
Reviewed-by: Maurice Kalinowski <maurice.kalinowski@qt.io>

2 files changed, 22 insertions, 6 deletions

diff --git a/src/network/socket/qnativesocketengine_winrt.cpp b/src/network/socket/qnativesocketengine_winrt.cpp
index 4470d19d8c..e427b19896 100644
--- a/src/network/socket/qnativesocketengine_winrt.cpp
+++ b/src/network/socket/qnativesocketengine_winrt.cpp
@@ -548,7 +548,7 @@ QNativeSocketEngine::QNativeSocketEngine(QObject *parent)
 #endif
 
     connect(this, SIGNAL(connectionReady()), SLOT(connectionNotification()), Qt::QueuedConnection);
-    connect(this, SIGNAL(readReady()), SLOT(readNotification()), Qt::QueuedConnection);
+    connect(this, SIGNAL(readReady()), SLOT(processReadReady()), Qt::QueuedConnection);
     connect(this, SIGNAL(writeReady()), SLOT(writeNotification()), Qt::QueuedConnection);
     connect(d->worker, &SocketEngineWorker::connectOpFinished,
             this, &QNativeSocketEngine::handleConnectOpFinished, Qt::QueuedConnection);
@@ -872,12 +872,15 @@ void QNativeSocketEngine::close()
     if (d->closingDown)
         return;
 
-    d->closingDown = true;
+    if (d->pendingReadNotification)
+        processReadReady();
 
+    d->closingDown = true;
 
     d->notifyOnRead = false;
     d->notifyOnWrite = false;
     d->notifyOnException = false;
+    d->emitReadReady = false;
 
     HRESULT hr;
     if (d->socketType == QAbstractSocket::TcpSocket) {
@@ -1019,8 +1022,10 @@ qint64 QNativeSocketEngine::read(char *data, qint64 maxlen)
             << copyLength << "of" << d->worker->pendingData.length() << "bytes";
         readData = d->worker->pendingData.left(maxlen);
         d->worker->pendingData.remove(0, maxlen);
-        if (d->notifyOnRead)
+        if (d->notifyOnRead) {
+            d->pendingReadNotification = true;
             emit readReady();
+        }
     }
     mutexLocker.unlock();
 
@@ -1369,6 +1374,7 @@ void QNativeSocketEngine::handleNewData()
         if (d->socketType == QAbstractSocket::UdpSocket && !d->worker->emitDataReceived)
             return;
         qCDebug(lcNetworkSocketVerbose) << this << Q_FUNC_INFO << "Emitting readReady";
+        d->pendingReadNotification = true;
         emit readReady();
         d->worker->emitDataReceived = false;
         d->emitReadReady = false;
@@ -1389,9 +1395,17 @@ void QNativeSocketEngine::handleTcpError(QAbstractSocket::SocketError error)
     }
 
     d->setError(error, errorString);
-    d->socketState = QAbstractSocket::UnconnectedState;
-    if (d->notifyOnRead)
-        emit readReady();
+    close();
+}
+
+void QNativeSocketEngine::processReadReady()
+{
+    Q_D(QNativeSocketEngine);
+    if (d->closingDown)
+        return;
+
+    d->pendingReadNotification = false;
+    readNotification();
 }
 
 bool QNativeSocketEnginePrivate::createNewSocket(QAbstractSocket::SocketType socketType, QAbstractSocket::NetworkLayerProtocol &socketProtocol)
diff --git a/src/network/socket/qnativesocketengine_winrt_p.h b/src/network/socket/qnativesocketengine_winrt_p.h
index f47e2a7dd7..6688bfe35c 100644
--- a/src/network/socket/qnativesocketengine_winrt_p.h
+++ b/src/network/socket/qnativesocketengine_winrt_p.h
@@ -184,6 +184,7 @@ private slots:
                                  WinRTSocketEngine::ErrorString errorString);
     void handleNewData();
     void handleTcpError(QAbstractSocket::SocketError error);
+    void processReadReady();
 
 private:
     Q_DECLARE_PRIVATE(QNativeSocketEngine)
@@ -228,6 +229,7 @@ private:
     EventRegistrationToken connectionToken;
 
     bool emitReadReady = true;
+    bool pendingReadNotification = false;
 
     HRESULT handleClientConnection(ABI::Windows::Networking::Sockets::IStreamSocketListener *tcpListener,
                                    ABI::Windows::Networking::Sockets::IStreamSocketListenerConnectionReceivedEventArgs *args);