Ratsnest is recalculated after global deletion of tracks and after importing a netlist.

pcbnew/dialogs/dialog_global_deletion.cpp

@@ -254,6 +254,9 @@ void DIALOG_GLOBAL_DELETION::AcceptPcbDelete( )
         if( gen_rastnest )
             m_Parent->Compile_Ratsnest( NULL, true );
 
+        if( m_Parent->IsGalCanvasActive() )
+            pcb->GetRatsnest()->Recalculate();
+
     }
 
     m_Parent->GetCanvas()->Refresh();

pcbnew/ratsnest_data.cpp

@@ -1009,6 +1009,8 @@ void RN_DATA::ProcessBoard()
         if( netCode > 0 )
             m_nets[netCode].AddItem( zone );
     }
+
+    Recalculate();
 }