Q{LocalSocket|Process}/Win: handle write errors

To match the Unix behavior, we should emit errorOccurred() signal and
close the channel if the write operation fails.

Change-Id: Iac3acb18dbbfe6e7e8afb2555d9adaff1fe98d0f
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@gmx.de>
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>

src/corelib/io/qprocess_p.h

@@ -287,6 +287,7 @@ public:
 #ifdef Q_OS_WIN
     qint64 pipeWriterBytesToWrite() const;
     void _q_bytesWritten(qint64 bytes);
+    void _q_writeFailed();
 #else
     bool _q_canWrite();
     bool writeToStdin();

src/corelib/io/qprocess_win.cpp

@@ -841,6 +841,8 @@ qint64 QProcess::writeData(const char *data, qint64 len)
         d->stdinChannel.writer = new QWindowsPipeWriter(d->stdinChannel.pipe[1], this);
         QObjectPrivate::connect(d->stdinChannel.writer, &QWindowsPipeWriter::bytesWritten,
                                 d, &QProcessPrivate::_q_bytesWritten);
+        QObjectPrivate::connect(d->stdinChannel.writer, &QWindowsPipeWriter::writeFailed,
+                                d, &QProcessPrivate::_q_writeFailed);
     }
 
     if (d->isWriteChunkCached(data, len))
@@ -872,6 +874,12 @@ void QProcessPrivate::_q_bytesWritten(qint64 bytes)
         closeWriteChannel();
 }
 
+void QProcessPrivate::_q_writeFailed()
+{
+    closeWriteChannel();
+    setErrorAndEmit(QProcess::WriteError);
+}
+
 // Use ShellExecuteEx() to trigger an UAC prompt when CreateProcess()fails
 // with ERROR_ELEVATION_REQUIRED.
 static bool startDetachedUacPrompt(const QString &programIn, const QStringList &arguments,

src/corelib/io/qwindowspipewriter.cpp

@@ -341,6 +341,7 @@ bool QWindowsPipeWriter::consumePendingAndEmit(bool allowWinActPosting)
         if (alive) {
             writeBuffer.clear();
             completionState = WriteDisabled;
+            emit writeFailed();
         }
     } else if (emitBytesWritten) {
         emit bytesWritten(numberOfBytesWritten);

src/corelib/io/qwindowspipewriter_p.h

@@ -78,6 +78,7 @@ public:
 
 Q_SIGNALS:
     void bytesWritten(qint64 bytes);
+    void writeFailed();
 
 protected:
     bool event(QEvent *e) override;

src/network/socket/qlocalsocket_p.h

@@ -137,6 +137,7 @@ public:
     void _q_bytesWritten(qint64 bytes);
     void _q_pipeClosed();
     void _q_winError(ulong windowsError, const QString &function);
+    void _q_writeFailed();
     HANDLE handle;
     QWindowsPipeWriter *pipeWriter;
     QWindowsPipeReader *pipeReader;

src/network/socket/qlocalsocket_win.cpp

@@ -310,6 +310,8 @@ qint64 QLocalSocket::writeData(const char *data, qint64 len)
         d->pipeWriter = new QWindowsPipeWriter(d->handle, this);
         QObjectPrivate::connect(d->pipeWriter, &QWindowsPipeWriter::bytesWritten,
                                 d, &QLocalSocketPrivate::_q_bytesWritten);
+        QObjectPrivate::connect(d->pipeWriter, &QWindowsPipeWriter::writeFailed,
+                                d, &QLocalSocketPrivate::_q_writeFailed);
     }
 
     if (d->isWriteChunkCached(data, len))
@@ -455,6 +457,16 @@ void QLocalSocketPrivate::_q_bytesWritten(qint64 bytes)
         q->disconnectFromServer();
 }
 
+void QLocalSocketPrivate::_q_writeFailed()
+{
+    Q_Q(QLocalSocket);
+    error = QLocalSocket::PeerClosedError;
+    errorString = QLocalSocket::tr("Remote closed");
+    emit q->errorOccurred(error);
+
+    _q_pipeClosed();
+}
+
 qintptr QLocalSocket::socketDescriptor() const
 {
     Q_D(const QLocalSocket);

tests/auto/network/socket/qlocalsocket/tst_qlocalsocket.cpp

@@ -1531,6 +1531,7 @@ void tst_QLocalSocket::writeToDisconnected()
     QVERIFY(server.listen("writeToDisconnected"));
 
     QLocalSocket client;
+    QSignalSpy spyError(&client, SIGNAL(errorOccurred(QLocalSocket::LocalSocketError)));
     client.connectToServer("writeToDisconnected");
     QVERIFY(client.waitForConnected(3000));
     QVERIFY(server.waitForNewConnection(3000));
@@ -1548,6 +1549,7 @@ void tst_QLocalSocket::writeToDisconnected()
 
     QCOMPARE(client.bytesToWrite(), qint64(1));
     QVERIFY(!client.waitForBytesWritten());
+    QCOMPARE(spyError.count(), 1);
     QCOMPARE(client.state(), QLocalSocket::UnconnectedState);
 }