pruner caches raised NoneType exception

[Zhou ShaoYu]

Set image_cache_max_size = 1 and cache some images which size bigger than image_cache_max_size,
and then run command glance-cache-pruner.
It raised exception NoneType:
Traceback (most recent call last):
  File "/usr/local/bin/glance-cache-pruner", line 7, in <module>
    execfile(__file__)
  File "/root/glance-2012.2/bin/glance-cache-pruner", line 54, in <module>
    app.run()
  File "/root/glance-2012.2/glance/image_cache/pruner.py", line 28, in run
    self.cache.prune()
  File "/root/glance-2012.2/glance/image_cache/__init__.py", line 186, in prune
    entry = self.driver.get_least_recently_accessed()
  File "/root/glance-2012.2/glance/image_cache/drivers/sqlite.py", line 275, in get_least_recently_accessed
    image_id = cur.fetchone()[0]
TypeError: 'NoneType' object has no attribute '__getitem__'

It's not fixed in folsom.

By the way,does it have config option for auto pruner image cache when glance cache a new image?I can cache images without max_size restricted.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/12174

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/12174
Committed: http://github.com/openstack/glance/commit/abcff5b5f5b2b89bf788f6e5447a85c320e5a26c
Submitter: Jenkins
Branch: master

commit abcff5b5f5b2b89bf788f6e5447a85c320e5a26c
Author: Brian Waldon <email address hidden>
Date: Wed Aug 29 21:17:46 2012 -0700

    Catch pruner exception when no images are cached

    This handles a situation where the pruner would raise an exception when
    the image_cache_max_size was set lower than the size of the last image.

    Fixes bug 1039854

    Change-Id: I4a6c164e9f821f1250314974f829f058fbd02863