Ensure that NullBooleanField displays the appropriate icon for null values in admin changelists. Refs #13071.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@12746 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/contrib/admin/util.py

@@ -337,12 +337,14 @@ def display_for_field(value, field):
 
     if field.flatchoices:
         return dict(field.flatchoices).get(value, EMPTY_CHANGELIST_VALUE)
+    # NullBooleanField needs special-case null-handling, so it comes
+    # before the general null test.
+    elif isinstance(field, models.BooleanField) or isinstance(field, models.NullBooleanField):
+        return _boolean_icon(value)
     elif value is None:
         return EMPTY_CHANGELIST_VALUE
     elif isinstance(field, models.DateField) or isinstance(field, models.TimeField):
         return formats.localize(value)
-    elif isinstance(field, models.BooleanField) or isinstance(field, models.NullBooleanField):
-        return _boolean_icon(value)
     elif isinstance(field, models.DecimalField):
         return formats.number_format(value, field.decimal_places)
     elif isinstance(field, models.FloatField):

tests/regressiontests/admin_util/tests.py

@@ -1,6 +1,7 @@
 from datetime import datetime
 import unittest
 
+from django.conf import settings
 from django.db import models
 from django.utils.formats import localize
 from django.test import TestCase
@@ -131,8 +132,11 @@ class UtilTests(unittest.TestCase):
         display_value = display_for_field(None, models.TimeField())
         self.assertEqual(display_value, EMPTY_CHANGELIST_VALUE)
 
+        # Regression test for #13071: NullBooleanField has special
+        # handling.
         display_value = display_for_field(None, models.NullBooleanField())
-        self.assertEqual(display_value, EMPTY_CHANGELIST_VALUE)
+        expected = u'<img src="%simg/admin/icon-unknown.gif" alt="None" />' % settings.ADMIN_MEDIA_PREFIX
+        self.assertEqual(display_value, expected)
 
         display_value = display_for_field(None, models.DecimalField())
         self.assertEqual(display_value, EMPTY_CHANGELIST_VALUE)

tests/regressiontests/admin_views/models.py

@@ -464,11 +464,13 @@ class Post(models.Model):
     title = models.CharField(max_length=100)
     content = models.TextField()
     posted = models.DateField(default=datetime.date.today)
+    public = models.NullBooleanField()
 
     def awesomeness_level(self):
         return "Very awesome."
 
 class PostAdmin(admin.ModelAdmin):
+    list_display = ['title', 'public']
     readonly_fields = ('posted', 'awesomeness_level', 'coolness', lambda obj: "foo")
 
     inlines = [

tests/regressiontests/admin_views/tests.py

@@ -253,6 +253,15 @@ class AdminViewBasicTest(TestCase):
             "Changelist filter isn't showing options contained inside a model field 'choices' option named group."
         )
 
+    def testChangeListNullBooleanDisplay(self):
+        Post.objects.create(public=None)
+        # This hard-codes the URl because it'll fail if it runs
+        # against the 'admin2' custom admin (which doesn't have the
+        # Post model).
+        response = self.client.get("/test_admin/admin/admin_views/post/")
+        self.failUnless('icon-unknown.gif' in response.content)
+        print "Passed"
+
 class SaveAsTests(TestCase):
     fixtures = ['admin-views-users.xml','admin-views-person.xml']