[patch] FilePathField gives no blank option in admin when blank=True is set

[Adam Endicott]

I have a model with this field:

image = models.FilePathField(path='/my/path', blank=True, null=True)

In the admin interface, the image field shows up dimmed like the rest
of the optional fields. However the select list lists all the files in
/my/path, without any blank option. So you are in effect forced to
select a file.

The patch adds models.BLANK_CHOICE_DASH to the choices list if is_required is false.

(django-users thread: ​http://groups.google.com/group/django-users/browse_frm/thread/9988c0119c95dda9/#)

[Malcolm Tredinnick]

(In [3146]) Fixed #1756 -- Permit selecting no file in a FilePathField with blank = True.
Thanks to Adam Endicott for the patch.

[Adrian Holovaty]

This patch is unacceptable because the form layer shouldn't be importing from the database layer.