Applied patch2 for #1016

git-svn-id: http://svn.osgeo.org/qgis/trunk@9968 c8812cc2-4d05-0410-92ff-de0c093fc19c

Author: mhugent

src/gui/qgsmapcanvas.cpp

@@ -811,8 +811,8 @@ void QgsMapCanvas::resizeEvent( QResizeEvent * e )
     int height = lastSize.height();
     lastSize = QSize( -1, -1 );
 
-    //set map size before scene size seems to solve the white box problem
-    //when moving rubber bands
+    //set map size before scene size helps keep scene indexes updated properly
+    // this was the cause of rubberband artifacts
     mMap->resize( QSize( width, height ) );
     mScene->setSceneRect( QRectF( 0, 0, width, height ) );
 

src/gui/qgsmapcanvasmap.cpp

@@ -48,6 +48,8 @@ QRectF QgsMapCanvasMap::boundingRect() const
 
 void QgsMapCanvasMap::resize( QSize size )
 {
+  prepareGeometryChange();	// to keep QGraphicsScene indexes up to date on size change
+
   mPixmap = QPixmap( size );
   mImage = QImage( size, QImage::Format_RGB32 );	// temporary image - build it here so it is available when switching from QPixmap to QImage rendering
   mCanvas->mapRenderer()->setOutputSize( size, mPixmap.logicalDpiX() );