From: Tony Mack <tmack@cs.princeton.edu>
Date: Wed, 6 Jan 2010 18:12:10 +0000 (+0000)
Subject: in urn_to_hrn() and hrn_to_urn() if argument is None, just return it
X-Git-Tag: sfa-0.9-9~36
X-Git-Url: http://git.onelab.eu/?a=commitdiff_plain;h=2ec68cc1c6b393d7db13767b4cc99eb5dbd0c039;p=sfa.git

in urn_to_hrn() and hrn_to_urn() if argument is None, just return it
---

diff --git a/sfa/util/namespace.py b/sfa/util/namespace.py
index 61b05b91..2e4b8975 100644
--- a/sfa/util/namespace.py
+++ b/sfa/util/namespace.py
@@ -57,8 +57,9 @@ def urn_to_hrn(urn):
     """
 
     # if this is already a hrn dont do anything
-    if not urn.startswith(URN_PREFIX):
+    if not urn or not urn.startswith(URN_PREFIX):
         return urn, None
+
     name = urn[len(URN_PREFIX):]
     hrn_parts = name.split("+")
     
@@ -79,7 +80,7 @@ def hrn_to_urn(hrn, type=None):
     convert an hrn and type to a urn string
     """
     # if  this is already a urn dont do anything 
-    if hrn.startswith(URN_PREFIX):
+    if not hrn or hrn.startswith(URN_PREFIX):
         return hrn
 
     authority = get_authority(hrn)