Fixed #7582: Removed checks that prevented null=True ForeignKey fields from being sortable in Admin. Post queryset-refactor there seems no reason to disallow this.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@9080 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/contrib/admin/templatetags/admin_list.py

@@ -115,10 +115,6 @@ def result_headers(cl):
 
             # So this _is_ a sortable non-field.  Go to the yield
             # after the else clause.
-        else:
-            if isinstance(f.rel, models.ManyToOneRel) and f.null:
-                yield {"text": f.verbose_name}
-                continue
         else:
             header = f.verbose_name
 

django/contrib/admin/views/main.py

@@ -162,7 +162,6 @@ class ChangeList(object):
                     except AttributeError:
                         pass
                 else:
-                    if not isinstance(f.rel, models.ManyToOneRel) or not f.null:
                     order_field = f.name
             except (IndexError, ValueError):
                 pass # Invalid ordering specified. Just use the default.