[1.2.X] Fixed #14982 -- Ensure that EMPTY_CHANGELIST_VALUE is honored for nullable foreign keys. Thanks to marcob for the report and fix, and to sontek for the test case.

Backport of r15286 from trunk.

git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.2.X@15287 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/contrib/admin/templatetags/admin_list.py

@@ -157,7 +157,11 @@ def items_for_result(cl, result, form):
                 if value is None:
                     result_repr = EMPTY_CHANGELIST_VALUE
                 if isinstance(f.rel, models.ManyToOneRel):
-                    result_repr = escape(getattr(result, f.name))
+                    field_val = getattr(result, f.name)
+                    if field_val is None:
+                        result_repr = EMPTY_CHANGELIST_VALUE
+                    else:
+                        result_repr = escape(field_val)
                 else:
                     result_repr = display_for_field(value, f)
                 if isinstance(f, models.DateField) or isinstance(f, models.TimeField):

tests/regressiontests/admin_changelist/models.py

@@ -5,5 +5,5 @@ class Parent(models.Model):
     name = models.CharField(max_length=128)
 
 class Child(models.Model):
-    parent = models.ForeignKey(Parent, editable=False)
-    name = models.CharField(max_length=30, blank=True)
+    parent = models.ForeignKey(Parent, editable=False, null=True)
+    name = models.CharField(max_length=30, blank=True)

tests/regressiontests/admin_changelist/tests.py

@@ -17,6 +17,26 @@ class ChangeListTests(TransactionTestCase):
                 m.list_select_related, m.list_per_page, m.list_editable, m)
         self.assertEqual(cl.query_set.query.select_related, {'parent': {'name': {}}})
 
+    def test_result_list_empty_changelist_value(self):
+        """
+        Regression test for #14982: EMPTY_CHANGELIST_VALUE should be honored
+        for relationship fields
+        """
+        new_child = Child.objects.create(name='name', parent=None)
+        request = MockRequest()
+        m = ChildAdmin(Child, admin.site)
+        cl = ChangeList(request, Child, m.list_display, m.list_display_links,
+                m.list_filter, m.date_hierarchy, m.search_fields,
+                m.list_select_related, m.list_per_page, m.list_editable, m)
+        cl.formset = None
+        template = Template('{% load admin_list %}{% spaceless %}{% result_list cl %}{% endspaceless %}')
+        context = Context({'cl': cl})
+        table_output = template.render(context)
+        row_html = '<tbody><tr class="row1"><td><input type="checkbox" class="action-select" value="1" name="_selected_action" /></td><th><a href="1/">name</a></th><td>(None)</td></tr></tbody>'
+        self.assertFalse(table_output.find(row_html) == -1,
+            'Failed to find expected row element: %s' % table_output)
+
+
     def test_result_list_html(self):
         """
         Verifies that inclusion tag result_list generates a table when with