[banshee] PlayerEngine: Fix NRE when current track doesn't have a Uri (bgo#639603)

[Bertrand Lorentz <blorentz src gnome org>]

commit 3823cafc119f83c7a6a596943300fc80fb07f322
Author: Sjoerd Simons <sjoerd simons collabora co uk>
Date:   Sat Jan 15 14:42:15 2011 +0000

    PlayerEngine: Fix NRE when current track doesn't have a Uri (bgo#639603)
    
    Signed-off-by: Bertrand Lorentz <bertrand lorentz gmail com>

 .../Banshee.MediaEngine/PlayerEngine.cs            |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/src/Core/Banshee.Services/Banshee.MediaEngine/PlayerEngine.cs b/src/Core/Banshee.Services/Banshee.MediaEngine/PlayerEngine.cs
index 5365747..26579bf 100644
--- a/src/Core/Banshee.Services/Banshee.MediaEngine/PlayerEngine.cs
+++ b/src/Core/Banshee.Services/Banshee.MediaEngine/PlayerEngine.cs
@@ -233,7 +233,8 @@ namespace Banshee.MediaEngine
 
         protected void OnTagFound (StreamTag tag)
         {
-            if (tag.Equals (StreamTag.Zero) || current_track == null || current_track.Uri.IsFile) {
+            if (tag.Equals (StreamTag.Zero) || current_track == null
+                || (current_track.Uri != null && current_track.Uri.IsFile)) {
                 return;
             }