Return after an error of the async write operation

Tested on Windows 8 using the on-board and the USB serial
ports and using Qt4 and Qt5.

Change-Id: Idd25b81c9b6b2cd0b94e83fe30e6e7dad4dddfd6
Reviewed-by: Sergey Belyashov <Sergey.Belyashov@gmail.com>
Reviewed-by: Denis Shienkov <denis.shienkov@gmail.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/src/serialport/qserialport_win.cpp b/src/serialport/qserialport_win.cpp
index 0f453f5..9b04083 100644
--- a/src/serialport/qserialport_win.cpp
+++ b/src/serialport/qserialport_win.cpp
@@ -620,10 +620,12 @@ void QSerialPortPrivate::_q_completeAsyncWrite()
 {
     Q_Q(QSerialPort);
 
+    writeStarted = false;
     DWORD numberOfBytesTransferred = 0;
     if (!::GetOverlappedResult(handle, &writeCompletionOverlapped, &numberOfBytesTransferred, FALSE)) {
         numberOfBytesTransferred = 0;
         q->setError(decodeSystemError());
+        return;
     }
 
     if (numberOfBytesTransferred > 0) {
@@ -631,7 +633,6 @@ void QSerialPortPrivate::_q_completeAsyncWrite()
         emit q->bytesWritten(numberOfBytesTransferred);
     }
 
-    writeStarted = false;
     startAsyncWrite();
 }