use a lookup that has all the apps

apps/amo/__init__.py

@@ -219,6 +219,7 @@ APPS = dict((app.short, app) for app in _apps)
 APP_IDS = dict((app.id, app) for app in _apps)
 APP_GUIDS = dict((app.guid, app) for app in _apps)
 APPS_RETIRED = dict([(MOZILLA.short, MOZILLA)])
+APPS_ALL = dict((app.id, app) for app in _apps + (MOZILLA,))
 
 
 # Platforms

apps/applications/models.py

@@ -17,7 +17,7 @@ class Application(amo.models.ModelBase):
         db_table = 'applications'
 
     def __unicode__(self):
-        return unicode(amo.APP_IDS[self.id].pretty)
+        return unicode(amo.APPS_ALL[self.id].pretty)
 
 
 class AppVersion(amo.models.ModelBase):