Fixed #16027 -- Added app_label to ContentType.__str__().

django/contrib/admin/templates/admin/index.html

@@ -73,7 +73,7 @@
                 {% endif %}
                 <br>
                 {% if entry.content_type %}
-                    <span class="mini quiet">{% filter capfirst %}{{ entry.content_type }}{% endfilter %}</span>
+                    <span class="mini quiet">{% filter capfirst %}{{ entry.content_type.name }}{% endfilter %}</span>
                 {% else %}
                     <span class="mini quiet">{% trans 'Unknown content' %}</span>
                 {% endif %}

django/contrib/auth/models.py

@@ -71,11 +71,7 @@ class Permission(models.Model):
                     'codename')
 
     def __str__(self):
-        return "%s | %s | %s" % (
-            self.content_type.app_label,
-            self.content_type,
-            self.name,
-        )
+        return '%s | %s' % (self.content_type, self.name)
 
     def natural_key(self):
         return (self.codename,) + self.content_type.natural_key()

django/contrib/contenttypes/models.py

@@ -142,7 +142,7 @@ class ContentType(models.Model):
         unique_together = (('app_label', 'model'),)
 
     def __str__(self):
-        return self.name
+        return self.app_labeled_name
 
     @property
     def name(self):
@@ -151,6 +151,13 @@ class ContentType(models.Model):
             return self.model
         return str(model._meta.verbose_name)
 
+    @property
+    def app_labeled_name(self):
+        model = self.model_class()
+        if not model:
+            return self.model
+        return '%s | %s' % (model._meta.app_label, model._meta.verbose_name)
+
     def model_class(self):
         """Return the model class for this type of content."""
         try:

docs/releases/3.0.txt

@@ -285,7 +285,8 @@ Django 3.0, we're removing these APIs at this time.
 Miscellaneous
 -------------
 
-* ...
+* ``ContentType.__str__()`` now includes the model's ``app_label`` to
+  disambiguate model's with the same name in different apps.
 
 .. _deprecated-features-3.0:
 

tests/contenttypes_tests/test_models.py

@@ -201,7 +201,15 @@ class ContentTypesTests(TestCase):
 
     def test_str(self):
         ct = ContentType.objects.get(app_label='contenttypes_tests', model='site')
-        self.assertEqual(str(ct), 'site')
+        self.assertEqual(str(ct), 'contenttypes_tests | site')
+
+    def test_app_labeled_name(self):
+        ct = ContentType.objects.get(app_label='contenttypes_tests', model='site')
+        self.assertEqual(ct.app_labeled_name, 'contenttypes_tests | site')
+
+    def test_app_labeled_name_unknown_model(self):
+        ct = ContentType(app_label='contenttypes_tests', model='unknown')
+        self.assertEqual(ct.app_labeled_name, 'unknown')
 
 
 class TestRouter:

tests/i18n/contenttypes/tests.py

@@ -20,6 +20,6 @@ class ContentTypeTests(TestCase):
     def test_verbose_name(self):
         company_type = ContentType.objects.get(app_label='i18n', model='company')
         with translation.override('en'):
-            self.assertEqual(str(company_type), 'Company')
+            self.assertEqual(str(company_type), 'i18n | Company')
         with translation.override('fr'):
-            self.assertEqual(str(company_type), 'Société')
+            self.assertEqual(str(company_type), 'i18n | Société')

tests/multiple_database/tests.py

@@ -840,8 +840,8 @@ class QueryTestCase(TestCase):
 
         # Set a foreign key with an object from a different database
         msg = (
-            'Cannot assign "<ContentType: book>": the current database router '
-            'prevents this relation.'
+            'Cannot assign "<ContentType: multiple_database | book>": the '
+            'current database router prevents this relation.'
         )
         with self.assertRaisesMessage(ValueError, msg):
             review1.content_object = dive