Fixed #12550 -- better handling with choices and null fields when displaying read-only values

Thanks Jacques Beaurain for the report and patch.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@12148 bcc190cf-cafb-0310-a4f2-bffc1f526a37

3 files changed, 41 insertions, 0 deletions

diff --git a/tests/regressiontests/admin_util/__init__.py b/tests/regressiontests/admin_util/__init__.py
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/tests/regressiontests/admin_util/__init__.py
diff --git a/tests/regressiontests/admin_util/models.py b/tests/regressiontests/admin_util/models.py
new file mode 100644
index 0000000000..b40f364b76
--- /dev/null
+++ b/tests/regressiontests/admin_util/models.py
@@ -0,0 +1 @@
+# needed for tests
\ No newline at end of file
diff --git a/tests/regressiontests/admin_util/tests.py b/tests/regressiontests/admin_util/tests.py
new file mode 100644
index 0000000000..11e71e20ec
--- /dev/null
+++ b/tests/regressiontests/admin_util/tests.py
@@ -0,0 +1,40 @@
+import unittest
+
+from django.db import models
+
+from django.contrib import admin
+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 handle None
+        value.
+        """
+        display_value = display_for_field(None, models.CharField())
+        self.assertEqual(display_value, EMPTY_CHANGELIST_VALUE)
+
+        display_value = display_for_field(None, models.CharField(
+            choices=(
+                (None, "test_none"),
+            )
+        ))
+        self.assertEqual(display_value, "test_none")
+
+        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)