vidjil_utils.py, anonymization: unicode decoding of patient name

If the patient name has some unicode characters, the manipulated string has to be a python unicode string.
We should one day ensure that all strings are handled as unicode both in the database and in web2py.

server/web2py/applications/vidjil/modules/vidjil_utils.py

@@ -46,6 +46,12 @@ def anon(patient_id, user_id):
     first_name = db.patient[patient_id].first_name
     
     if auth.has_permission("anon", "patient", patient_id, user_id):
-        return last_name + " " + first_name
+        name = last_name + " " + first_name
     else:
-        return last_name[:3]
+        try:
+            ln = unicode(last_name, 'utf-8')
+        except UnicodeDecodeError:
+            ln = last_name
+        name = ln[:3]
+
+    return name