Add comment about odd-looking code
@@ -603,6 +603,8 @@ def maybe_update_error_store(view):
new_errors = []
for error in errors:
uid = error['uid']
+ # XXX: Why keep the error in the store when we don't have
+ # a region key for it in the store?
key = uid_key_map.get(uid, None)
region = head(view.get_regions(key)) if key else None
if region is None or region == error['region']:
