AttributeError: MetaDataGenerator instance has no attribute 'oldData'

Issue

createrepo gives error if there is no new package added in the repository.

# createrepo -C --update /repo
Traceback (most recent call last):
  File "/usr/share/createrepo/genpkgmetadata.py", line 307, in <module>
    main(sys.argv[1:])
  File "/usr/share/createrepo/genpkgmetadata.py", line 296, in main
    mdgen.cleanup()
  File "/usr/lib/python2.6/site-packages/createrepo/__init__.py", line 1208, in cleanup
    self._cleanup_update_tmp_dir()
  File "/usr/lib/python2.6/site-packages/createrepo/__init__.py", line 1213, in _cleanup_update_tmp_dir
    self.oldData.cleanup()
AttributeError: MetaDataGenerator instance has no attribute 'oldData'