Make copy constructor and assignment operator of singleton classes private.

src/core/Config.h

@@ -34,6 +34,8 @@ private:
 
     QScopedPointer<QSettings> m_settings;
 
+    Q_DISABLE_COPY(Config)
+
     friend Config* config();
 };
 

src/core/DataPath.h

@@ -34,6 +34,8 @@ private:
 
     QString m_basePath;
 
+    Q_DISABLE_COPY(DataPath)
+
     friend DataPath* dataPath();
 };
 

src/core/DatabaseIcons.h

@@ -38,6 +38,8 @@ private:
     QVector<QImage> m_iconCache;
     QVector<QPixmapCache::Key> m_pixmapCacheKeys;
 
+    Q_DISABLE_COPY(DatabaseIcons)
+
     friend DatabaseIcons* databaseIcons();
 };
 

src/gui/FileDialog.h

@@ -40,6 +40,8 @@ private:
     FileDialog();
     QString m_nextFileName;
 
+    Q_DISABLE_COPY(FileDialog)
+
     friend FileDialog* fileDialog();
 };