Fixed possible block clearing in QWebSocketDataProcessor::process method

In QWebSocketDataProcessor::process() the signals text(binary)MessageReceived
are emitted before clear() method. If signal handler blocks loop
(for example, using QDialog::exec()), clear() will be called only after
resuming loop. It may lead to the data corruption due to the fact that
QWebSocketDataProcessor clearing won't be performed before the new data
arrived.

Task-number: QTBUG-55506
Change-Id: Ib7016a91d3987dec7c1af977b17f86a53568c413
Reviewed-by: Timur Pocheptsov <timur.pocheptsov@qt.io>

1 files changed, 9 insertions, 5 deletions

diff --git a/src/websockets/qwebsocketdataprocessor.cpp b/src/websockets/qwebsocketdataprocessor.cpp
index 520ecdc..d9fc550 100644
--- a/src/websockets/qwebsocketdataprocessor.cpp
+++ b/src/websockets/qwebsocketdataprocessor.cpp
@@ -182,12 +182,16 @@ void QWebSocketDataProcessor::process(QIODevice *pIoDevice)
                 }
 
                 if (frame.isFinalFrame()) {
-                    if (m_opCode == QWebSocketProtocol::OpCodeText)
-                        Q_EMIT textMessageReceived(m_textMessage);
-                    else
-                        Q_EMIT binaryMessageReceived(m_binaryMessage);
-                    clear();
                     isDone = true;
+                    if (m_opCode == QWebSocketProtocol::OpCodeText) {
+                        const QString textMessage(m_textMessage);
+                        clear();
+                        Q_EMIT textMessageReceived(textMessage);
+                    } else {
+                        const QByteArray binaryMessage(m_binaryMessage);
+                        clear();
+                        Q_EMIT binaryMessageReceived(binaryMessage);
+                    }
                 }
             }
         } else {