[rygel] external: Prevent critical if DisplayName is empty

[Jens Georg <jensgeorg src gnome org>]

commit 3b0c8fbfbd3ea5d8eb7d976872bae9ca389ed519
Author: Jens Georg <mail jensge org>
Date:   Thu Feb 9 15:45:55 2012 +0200

    external: Prevent critical if DisplayName is empty

 src/plugins/external/rygel-external-container.vala |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)
---
diff --git a/src/plugins/external/rygel-external-container.vala b/src/plugins/external/rygel-external-container.vala
index a2326c1..9991520 100644
--- a/src/plugins/external/rygel-external-container.vala
+++ b/src/plugins/external/rygel-external-container.vala
@@ -281,7 +281,10 @@ public class Rygel.External.Container : Rygel.MediaContainer,
                                          DBusProxyFlags.DO_NOT_LOAD_PROPERTIES);
             var props = yield props_iface.get_all (MediaContainerProxy.IFACE);
             var child_count = (uint) props.lookup ("ChildCount");
-            this.title = (string) props.lookup ("DisplayName");
+            var title = props.lookup ("DisplayName");
+            if (title != null) {
+                this.title = (string) title;
+            }
             this.child_count = (int) child_count;
         } catch (GLib.Error property_error) {
             warning ("Failed to update information about container '%s': %s",