[hyena/gtk3] Fix null exception in ListView Rendering

[Bertrand Lorentz <blorentz src gnome org>]

commit 6fe35872061729a89d5eb79a96d7e57b7cafbe1f
Author: Olivier Dufour <olivier duff gmail com>
Date:   Fri May 13 23:05:23 2011 +0200

    Fix null exception in ListView Rendering

 .../Hyena.Data.Gui/ListView/ListView_Rendering.cs  |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/Hyena.Gui/Hyena.Data.Gui/ListView/ListView_Rendering.cs b/Hyena.Gui/Hyena.Data.Gui/ListView/ListView_Rendering.cs
index 01b51cc..00d765e 100644
--- a/Hyena.Gui/Hyena.Data.Gui/ListView/ListView_Rendering.cs
+++ b/Hyena.Gui/Hyena.Data.Gui/ListView/ListView_Rendering.cs
@@ -61,7 +61,7 @@ namespace Hyena.Data.Gui
         }
 
         public override Pango.FontDescription FontDescription {
-            get { return cell_context.FontDescription; }
+            get { return cell_context  != null ? cell_context.FontDescription : null; }
         }
 
         private List<int> selected_rows = new List<int> ();