1 files changed, 21 insertions, 19 deletions

diff --git a/src/corelib/io/qlockfile_win.cpp b/src/corelib/io/qlockfile_win.cpp
index 00c8a85bcc..f9f29090d7 100644
--- a/src/corelib/io/qlockfile_win.cpp
+++ b/src/corelib/io/qlockfile_win.cpp
@@ -5,36 +5,28 @@
 **
 ** This file is part of the QtCore module of the Qt Toolkit.
 **
-** $QT_BEGIN_LICENSE:LGPL$
+** $QT_BEGIN_LICENSE:LGPL21$
 ** Commercial License Usage
 ** Licensees holding valid commercial Qt licenses may use this file in
 ** accordance with the commercial license agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
-** a written agreement between you and Digia.  For licensing terms and
-** conditions see http://qt.digia.com/licensing.  For further information
+** a written agreement between you and Digia. For licensing terms and
+** conditions see http://qt.digia.com/licensing. For further information
 ** use the contact form at http://qt.digia.com/contact-us.
 **
 ** GNU Lesser General Public License Usage
 ** Alternatively, this file may be used under the terms of the GNU Lesser
-** General Public License version 2.1 as published by the Free Software
-** Foundation and appearing in the file LICENSE.LGPL included in the
-** packaging of this file.  Please review the following information to
-** ensure the GNU Lesser General Public License version 2.1 requirements
-** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+** General Public License version 2.1 or version 3 as published by the Free
+** Software Foundation and appearing in the file LICENSE.LGPLv21 and
+** LICENSE.LGPLv3 included in the packaging of this file. Please review the
+** following information to ensure the GNU Lesser General Public License
+** requirements will be met: https://www.gnu.org/licenses/lgpl.html and
+** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
 **
 ** In addition, as a special exception, Digia gives you certain additional
-** rights.  These rights are described in the Digia Qt LGPL Exception
+** rights. These rights are described in the Digia Qt LGPL Exception
 ** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
 **
-** GNU General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU
-** General Public License version 3.0 as published by the Free Software
-** Foundation and appearing in the file LICENSE.GPL included in the
-** packaging of this file.  Please review the following information to
-** ensure the GNU General Public License version 3.0 requirements will be
-** met: http://www.gnu.org/copyleft/gpl.html.
-**
-**
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/
@@ -47,6 +39,7 @@
 #include "QtCore/qfileinfo.h"
 #include "QtCore/qdatetime.h"
 #include "QtCore/qdebug.h"
+#include "QtCore/qthread.h"
 
 QT_BEGIN_NAMESPACE
 
@@ -149,7 +142,16 @@ void QLockFile::unlock()
      if (!d->isLocked)
         return;
      CloseHandle(d->fileHandle);
-     QFile::remove(d->fileName);
+     int attempts = 0;
+     static const int maxAttempts = 500; // 500ms
+     while (!QFile::remove(d->fileName) && ++attempts < maxAttempts) {
+         // Someone is reading the lock file right now (on Windows this prevents deleting it).
+         QThread::msleep(1);
+     }
+     if (attempts == maxAttempts) {
+        qWarning() << "Could not remove our own lock file" << d->fileName << ". Either other users of the lock file are reading it constantly for 500 ms, or we (no longer) have permissions to delete the file";
+        // This is bad because other users of this lock file will now have to wait for the stale-lock-timeout...
+     }
      d->lockError = QLockFile::NoError;
      d->isLocked = false;
 }