fix error on feed url for non-existant ticket
diff --git a/ForgeTracker/forgetracker/tests/functional/test_root.py b/ForgeTracker/forgetracker/tests/functional/test_root.py
index 2d869f4..4ed4620 100644
--- a/ForgeTracker/forgetracker/tests/functional/test_root.py
+++ b/ForgeTracker/forgetracker/tests/functional/test_root.py
@@ -1624,6 +1624,8 @@
         assert 'Tis a reply' in r
         assert 'ticket discussion post content' in r
 
+        self.app.get('/bugs/9999/feed.rss', status=404)
+
     def test_bulk_edit_index(self):
         self.new_ticket(summary='test first ticket', status='open')
         self.new_ticket(summary='test second ticket', status='accepted')
diff --git a/ForgeTracker/forgetracker/tracker_main.py b/ForgeTracker/forgetracker/tracker_main.py
index d2dcc20..367de34 100644
--- a/ForgeTracker/forgetracker/tracker_main.py
+++ b/ForgeTracker/forgetracker/tracker_main.py
@@ -1397,6 +1397,8 @@
         Overrides :meth:`allura.controllers.feed.FeedController.get_feed`.
 
         """
+        if not self.ticket:
+            return None
         title = 'Recent changes to %d: %s' % (
             self.ticket.ticket_num, self.ticket.summary)
         return FeedArgs(