Py3.2: don't rely on binascii.unhexlify to convert under covers.

src/ZODB/blob.py

@@ -557,7 +557,7 @@ class BushyLayout(object):
     def path_to_oid(self, path):
         if self.blob_path_pattern.match(path) is None:
             raise ValueError("Not a valid OID path: `%s`" % path)
-        path = path.split(os.path.sep)
+        path = [bytes(x, 'ascii') for x in path.split(os.path.sep)]
         # Each path segment stores a byte in hex representation. Turn it into
         # an int and then get the character for our byte string.
         oid = b''.join(binascii.unhexlify(byte[2:]) for byte in path)

src/ZODB/utils.py

@@ -164,7 +164,9 @@ def oid_repr(oid):
         return repr(oid)
 
 def repr_to_oid(repr):
-    if repr.startswith("0x"):
+    if not isinstance(repr, bytes):
+        repr = bytes(repr, 'ascii')
+    if repr.startswith(b"0x"):
         repr = repr[2:]
     as_bin = unhexlify(repr)
     as_bin = b"\x00"*(8-len(as_bin)) + as_bin