Fixing UUID coerce function for unicode non uuid form

If we use non uuid unicode user id in py27 env,
unicode error pop up when function is called.

Closes-bug: #1760918

Change-Id: Ic6b6308fb1960ec40407e6efde30137b64543e72
(cherry picked from commit b1d0b5d8)

oslo_versionedobjects/fields.py

@@ -349,7 +349,7 @@ class UUID(StringPattern):
         with warnings.catch_warnings():
             warnings.simplefilter("once")
             try:
-                uuid.UUID(str(value))
+                uuid.UUID(u"%s" % value)
             except Exception:
                 # This is to ensure no breaking behaviour for current
                 # users
@@ -360,9 +360,11 @@ class UUID(StringPattern):
                               "code to input valid UUIDs or accept "
                               "ValueErrors for invalid UUIDs. See "
                               "https://docs.openstack.org/oslo.versionedobjects/latest/reference/fields.html#oslo_versionedobjects.fields.UUIDField "  # noqa
-                              "for further details" % value, FutureWarning)
+                              "for further details" %
+                              repr(value).encode('utf8'),
+                              FutureWarning)
 
-            return str(value)
+            return u"%s" % value
 
 
 class MACAddress(StringPattern):

oslo_versionedobjects/tests/test_fields.py

+# -*- coding: utf-8 -*-
 #    Copyright 2013 Red Hat, Inc.
 #
 #    Licensed under the Apache License, Version 2.0 (the "License"); you may
@@ -284,6 +285,9 @@ class TestUUID(TestField):
             ('da66a411-af0e-4829-9b67-475017ddz152',
                 'da66a411-af0e-4829-9b67-475017ddz152'),
             ('fake_uuid', 'fake_uuid'),
+            (u'fake_uāid', u'fake_uāid'),
+            (b'fake_u\xe1id'.decode('latin_1'),
+                b'fake_u\xe1id'.decode('latin_1')),
             ('1', '1'),
             (1, '1')
         ]