Test if we correctly detect errors when writing.

tests/FailDevice.h

@@ -0,0 +1,43 @@
+/*
+ *  Copyright (C) 2015 Felix Geyer <debfx@fobos.de>
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 2 or (at your option)
+ *  version 3 of the License.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef KEEPASSX_FAILDEVICE_H
+#define KEEPASSX_FAILDEVICE_H
+
+#include <QBuffer>
+
+#include "core/Global.h"
+
+class FailDevice : public QBuffer
+{
+    Q_OBJECT
+
+public:
+    explicit FailDevice(int failAfter, QObject* parent = Q_NULLPTR);
+    bool open(QIODevice::OpenMode openMode) Q_DECL_OVERRIDE;
+
+protected:
+    qint64 readData(char* data, qint64 len) Q_DECL_OVERRIDE;
+    qint64 writeData(const char* data, qint64 len) Q_DECL_OVERRIDE;
+
+private:
+    int m_failAfter;
+    int m_readCount;
+    int m_writeCount;
+};
+
+#endif // KEEPASSX_FAILDEVICE_H