Fixed #28282 -- Fixed class-based indexes name for models that only inherit Model.

django/db/models/base.py

@@ -293,11 +293,12 @@ class ModelBase(type):
                 else:
                     new_class.add_to_class(field.name, copy.deepcopy(field))
 
-        if base_meta and base_meta.abstract and not abstract:
+        # Copy indexes so that index names are unique when models extend an
+        # abstract model.
         new_class._meta.indexes = [copy.deepcopy(idx) for idx in new_class._meta.indexes]
         # Set the name of _meta.indexes. This can't be done in
-            # Options.contribute_to_class() because fields haven't been added
-            # to the model at that point.
+        # Options.contribute_to_class() because fields haven't been added to
+        # the model at that point.
         for index in new_class._meta.indexes:
             if not index.name:
                 index.set_name_with_model(new_class)

docs/releases/1.11.3.txt

@@ -23,3 +23,6 @@ Bugfixes
   (:ticket:`28202`).
 
 * Fixed invalid HTML for a required ``AdminFileWidget`` (:ticket:`28278`).
+
+* Fixed model initialization to set the name of class-based model indexes
+  for models that only inherit ``models.Model`` (:ticket:`28282`).

tests/model_indexes/models.py

@@ -6,6 +6,9 @@ class Book(models.Model):
     author = models.CharField(max_length=50)
     pages = models.IntegerField(db_column='page_count')
 
+    class Meta:
+        indexes = [models.indexes.Index(fields=['title'])]
+
 
 class AbstractModel(models.Model):
     name = models.CharField(max_length=50)

tests/model_indexes/tests.py

@@ -83,6 +83,10 @@ class IndexesTests(SimpleTestCase):
         self.assertIsNot(index, new_index)
         self.assertEqual(index.fields, new_index.fields)
 
+    def test_name_set(self):
+        index_names = [index.name for index in Book._meta.indexes]
+        self.assertEqual(index_names, ['model_index_title_196f42_idx'])
+
     def test_abstract_children(self):
         index_names = [index.name for index in ChildModel1._meta.indexes]
         self.assertEqual(index_names, ['model_index_name_440998_idx'])