When retrieving a field by name, handle a missed case when the cache cannot be initialised yet.
When retrieving a field by name, handle a missed case when the cache cannot be
initialised yet.


git-svn-id: http://code.djangoproject.com/svn/django/trunk@7478 bcc190cf-cafb-0310-a4f2-bffc1f526a37

--HG--
extra : convert_revision : 5dc2abf4271ad620399828ce7a2916be143eea64

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