Index: src/app/legend/qgslegend.cpp
===================================================================
--- src/app/legend/qgslegend.cpp	(revision 13575)
+++ src/app/legend/qgslegend.cpp	(working copy)
@@ -363,13 +363,16 @@
 
   hideLine();
 
-  QTreeWidgetItem *destItem = mDropTarget;
-
   QgsLegendItem* origin = dynamic_cast<QgsLegendItem *>( mItemBeingMoved );
   mItemBeingMoved = NULL;
   QModelIndex oldIndex = indexFromItem( origin );
 
-  QgsLegendItem* dest = dynamic_cast<QgsLegendItem *>( destItem );
+  // check if the drop place is valid
+  QgsLegendItem* dest = NULL;
+  if ( mDropTarget )
+  {
+    dest = dynamic_cast<QgsLegendItem *>( mDropTarget );
+  }
 
   // no change?
   if ( !dest || !origin || ( dest == origin ) )
@@ -377,6 +380,15 @@
     checkLayerOrderUpdate();
     return;
   }
+  
+  // make sure you are able to drag the item
+  // to fix #2711, #2528, #2018
+  QgsLegendItem::DRAG_ACTION action = dest->accept( origin );  
+  if ( action == QgsLegendItem::NO_ACTION && mDropAction != NO_ACTION )
+  {
+    QgsDebugMsg( "Drag NO_ACTION" );
+    return;
+  }
 
   {
     // Do the actual move here.