Fixed a potential bug in case someone calls QgsMapCanvas::setOverview…

…(NULL)

git-svn-id: http://svn.osgeo.org/qgis/trunk/qgis@8667 c8812cc2-4d05-0410-92ff-de0c093fc19c

src/gui/qgsmapcanvas.cpp

@@ -319,10 +319,10 @@ void QgsMapCanvas::setOverview(QgsMapOverviewCanvas* overview)
     // map overview is not owned by map canvas so don't delete it...
   }
 
+  mMapOverview = overview;
+
   if (overview)
   {
-    mMapOverview = overview;
-
     // connect to the map render to copy its projection settings
     connect(mMapRender, SIGNAL(projectionsEnabled(bool)),
             overview,     SLOT(projectionsEnabled(bool)));