Fixed #14254 - More tests for storage backends
Fixed #14254 - More tests for storage backends

Thanks to steph for the patch, also to tobias for cleanups.

--HG--
extra : convert_revision : svn%3Abcc190cf-cafb-0310-a4f2-bffc1f526a37/django/trunk%4013852

adieu/django-nonrel,adieu/django-nonrel,adieu/django-nonrel