check we got a string for dump

git-svn-id: https://svn.erp5.org/repos/neo/branches/prototype3@151 71dcc9de-d417-0410-9af5-da40c76e7ee4

neo/util.py

@@ -2,10 +2,13 @@ from zlib import adler32
 
 def dump(s):
     """Dump a binary string in hex."""
+    if isinstance(s, str):
         ret = []
         for c in s:
             ret.append('%02x' % ord(c))
         return ''.join(ret)
+    else:
+        return repr(s)
 
 
 def makeChecksum(s):