Ticket #12550: django_nullvalue_adminlist_display.patch

django/contrib/admin/util.py

@@ -281 +281 @@
 def display_for_field(value, field):
     from django.contrib.admin.templatetags.admin_list import _boolean_icon
     from django.contrib.admin.views.main import EMPTY_CHANGELIST_VALUE
+    
+    if value is None:
+        return EMPTY_CHANGELIST_VALUE
+        
     if isinstance(field, models.DateField) or isinstance(field, models.TimeField):
         return formats.localize(value)
     elif isinstance(field, models.BooleanField) or isinstance(field, models.NullBooleanField):

tests/regressiontests/admin_util/models.py

@@ +1 @@
+from django.db import models
+
+        
+ No newline at end of file

tests/regressiontests/admin_util/tests.py

@@ +1 @@
+import unittest 
+from django.contrib import admin
+from django.db import models
+from django.contrib.admin.util import display_for_field
+from django.contrib.admin.views.main import EMPTY_CHANGELIST_VALUE
+
+class UtilTests(unittest.TestCase):
+    def test_null_display_for_field(self):
+        """
+        Regression test for #12550: display_for_field should not throw 
+        if None value is passed.
+        """
+        display_value = display_for_field(None, models.DateField())
+        self.assertEqual(display_value, EMPTY_CHANGELIST_VALUE)
+        
+        display_value = display_for_field(None, models.TimeField())
+        self.assertEqual(display_value, EMPTY_CHANGELIST_VALUE)
+        
+        display_value = display_for_field(None, models.NullBooleanField())
+        self.assertEqual(display_value, EMPTY_CHANGELIST_VALUE)
+        
+        display_value = display_for_field(None, models.DecimalField())
+        self.assertEqual(display_value, EMPTY_CHANGELIST_VALUE)
+        
+        display_value = display_for_field(None, models.FloatField())
+        self.assertEqual(display_value, EMPTY_CHANGELIST_VALUE)
+