Index: src/gui/qgsmapcanvas.cpp
===================================================================
--- src/gui/qgsmapcanvas.cpp	(revision 15676)
+++ src/gui/qgsmapcanvas.cpp	(working copy)
@@ -231,6 +231,7 @@
     return;
   }
 
+  mMapRenderer->setAllLayerSet(layers); 
   // create layer set
   QStringList layerSet, layerSetOverview;
 
Index: src/core/qgsmaprenderer.h
===================================================================
--- src/core/qgsmaprenderer.h	(revision 15676)
+++ src/core/qgsmaprenderer.h	(working copy)
@@ -24,6 +24,7 @@
 #include "qgis.h"
 #include "qgsrectangle.h"
 #include "qgsrendercontext.h"
+#include "../gui/qgsmapcanvas.h"
 
 class QDomDocument;
 class QDomNode;
@@ -206,6 +207,9 @@
 
     //! change current layer set
     void setLayerSet( const QStringList& layers );
+    
+    // set all layerset  including both visible and invisible layers 
+    void setAllLayerSet( QList<QgsMapCanvasLayer> &allLayers );
 
     //! updates extent of the layer set
     void updateFullExtent();
@@ -303,6 +307,9 @@
     //! stores array of layers to be rendered (identified by string)
     QStringList mLayerSet;
 
+    // stores array of layers both visible and invisible layers for calculating full extent 
+    QStringList mAllLayerSet; 
+    
     //! full extent of the layer set
     QgsRectangle mFullExtent;
 
Index: src/core/qgsmaprenderer.cpp
===================================================================
--- src/core/qgsmaprenderer.cpp	(revision 15676)
+++ src/core/qgsmaprenderer.cpp	(working copy)
@@ -840,8 +840,8 @@
 
   // iterate through the map layers and test each layers extent
   // against the current min and max values
-  QStringList::iterator it = mLayerSet.begin();
-  while ( it != mLayerSet.end() )
+  QStringList::iterator it = mAllLayerSet.begin();
+  while ( it != mAllLayerSet.end() )
   {
     QgsMapLayer * lyr = registry->mapLayer( *it );
     if ( lyr == NULL )
@@ -908,6 +908,22 @@
   return mLayerSet;
 }
 
+void QgsMapRenderer::setAllLayerSet( QList<QgsMapCanvasLayer> &allLayers )
+{
+  int i;
+  for ( i = 0; i < allLayers.size(); i++ )
+  {
+    QgsMapCanvasLayer &lyr = allLayers[i];
+    if ( !lyr.layer() )
+    {
+      continue;
+    }
+
+    mAllLayerSet.push_back( lyr.layer()->id() );
+  }
+  QgsDebugMsg ( " total layers present are " + QString :: number (mAllLayerSet.size()));
+}
+
 QgsOverlayObjectPositionManager* QgsMapRenderer::overlayManagerFromSettings()
 {
   QSettings settings;