QWindowsPipeWriter: do not clear the buffer in thread pool callback

In a blocking application, receiving the results of write operations
must be synchronized with the waitFor...() functions. But, clearing
the buffer in another thread can cause the code

  localsocket.write(...);
  QVERIFY(localsocket.bytesToWrite() > 0);

to fail unexpectedly, if the socket has been disconnected between
the calls.

So, defer resetting the buffer until checkForWrite() is called.

Change-Id: I8c21036aab6a4c56d02c0d9a18d4bbce52d724f4
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@gmx.de>

1 files changed, 27 insertions, 0 deletions

diff --git a/tests/auto/network/socket/qlocalsocket/tst_qlocalsocket.cpp b/tests/auto/network/socket/qlocalsocket/tst_qlocalsocket.cpp
index f537bd9157..519a7bfacb 100644
--- a/tests/auto/network/socket/qlocalsocket/tst_qlocalsocket.cpp
+++ b/tests/auto/network/socket/qlocalsocket/tst_qlocalsocket.cpp
@@ -132,6 +132,7 @@ private slots:
 
     void writeToClientAndDisconnect_data();
     void writeToClientAndDisconnect();
+    void writeToDisconnected();
 
     void debug();
     void bytesWrittenSignal();
@@ -1524,6 +1525,32 @@ void tst_QLocalSocket::writeToClientAndDisconnect()
     QCOMPARE(client.state(), QLocalSocket::UnconnectedState);
 }
 
+void tst_QLocalSocket::writeToDisconnected()
+{
+    QLocalServer server;
+    QVERIFY(server.listen("writeToDisconnected"));
+
+    QLocalSocket client;
+    client.connectToServer("writeToDisconnected");
+    QVERIFY(client.waitForConnected(3000));
+    QVERIFY(server.waitForNewConnection(3000));
+    QLocalSocket *serverSocket = server.nextPendingConnection();
+    QVERIFY(serverSocket);
+    serverSocket->abort();
+
+    QCOMPARE(client.state(), QLocalSocket::ConnectedState);
+    QVERIFY(client.putChar(0));
+
+#ifdef Q_OS_WIN
+    // Ensure the asynchronous write operation is finished.
+    QTest::qSleep(250);
+#endif
+
+    QCOMPARE(client.bytesToWrite(), qint64(1));
+    QVERIFY(!client.waitForBytesWritten());
+    QCOMPARE(client.state(), QLocalSocket::UnconnectedState);
+}
+
 void tst_QLocalSocket::debug()
 {
     // Make sure this compiles