QtSingleApplication: Bail out of read loop when peer disconnects

When messages are received while the event loop is inactive
(for example, when locked by a native dialog), it can happen
that a new connection is triggered which then goes into
unconnected state when the peer terminates. Add a check
to the loop and discard the connection in that case.

Task-number: QTSOLBUG-193
Change-Id: I7d5502cb411d2b967bd06fe8734b97fee54b7d18
Reviewed-by: Joni Poikelin <[email protected]>
Reviewed-by: Andy Shaw <[email protected]>

Author: FriedemannKleint

qtsingleapplication/src/qtlocalpeer.cpp

@@ -176,8 +176,17 @@ void QtLocalPeer::receiveConnection()
     if (!socket)
         return;
 
-    while (socket->bytesAvailable() < (int)sizeof(quint32))
+    while (true) {
+        if (socket->state() == QAbstractSocket::UnconnectedState) {
+            qWarning("QtLocalPeer: Peer disconnected");
+            delete socket;
+            return;
+        }
+        if (socket->bytesAvailable() >= qint64(sizeof(quint32)))
+            break;
         socket->waitForReadyRead();
+    }
+
     QDataStream ds(socket);
     QByteArray uMsg;
     quint32 remaining;