[brasero] Fix a small warning at run time

[Philippe Rouquier <philippr src gnome org>]

commit ecdfce6efe6d3e2ac0b128aa091df5f29171e750
Author: Philippe Rouquier <bonfire-app wanadoo fr>
Date:   Sun Nov 22 17:18:49 2009 +0100

    Fix a small warning at run time

 src/brasero-audio-disc.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/src/brasero-audio-disc.c b/src/brasero-audio-disc.c
index 8ad20d3..bfea0d9 100644
--- a/src/brasero-audio-disc.c
+++ b/src/brasero-audio-disc.c
@@ -236,6 +236,9 @@ brasero_audio_disc_is_empty (BraseroDisc *disc)
 	GtkTreeModel *model;
 
 	model = gtk_tree_view_get_model (GTK_TREE_VIEW (BRASERO_AUDIO_DISC (disc)->priv->tree));
+	if (!model)
+		return TRUE;
+
 	return gtk_tree_model_iter_n_children (model, NULL) != 0;
 }