Fixed #31703 -- Made makemigrations name all initial migrations "initial".

When the MigrationAutodetector creates more than one initial migration
in a app, name all initial migrations "initial" rather than the opaque
"auto_<DATE>_<TIME>" name.

Initial migrations that have a descriptive name continue to use the
descriptive name.

django/db/migrations/migration.py

@@ -192,7 +192,7 @@ class Migration:
         ):
             name = '_'.join(sorted(o.migration_name_fragment for o in self.operations))
         if name is None:
-            name = 'auto_%s' % get_migration_name_timestamp()
+            name = 'initial' if self.initial else 'auto_%s' % get_migration_name_timestamp()
         return name
 
 

tests/migrations/test_autodetector.py

@@ -612,6 +612,26 @@ class AutodetectorTests(TestCase):
         self.assertEqual(changes["otherapp"][0].name, "0002_pony_stable")
         self.assertEqual(changes["otherapp"][0].dependencies, [("otherapp", "0001_initial")])
 
+    def test_arrange_for_graph_with_multiple_initial(self):
+        # Make a fake graph.
+        graph = MigrationGraph()
+        # Use project state to make a new migration change set.
+        before = self.make_project_state([])
+        after = self.make_project_state([self.author_with_book, self.book, self.attribution])
+        autodetector = MigrationAutodetector(before, after, MigrationQuestioner({'ask_initial': True}))
+        changes = autodetector._detect_changes()
+        changes = autodetector.arrange_for_graph(changes, graph)
+
+        self.assertEqual(changes['otherapp'][0].name, '0001_initial')
+        self.assertEqual(changes['otherapp'][0].dependencies, [])
+        self.assertEqual(changes['otherapp'][1].name, '0002_initial')
+        self.assertCountEqual(
+            changes['otherapp'][1].dependencies,
+            [('testapp', '0001_initial'), ('otherapp', '0001_initial')],
+        )
+        self.assertEqual(changes['testapp'][0].name, '0001_initial')
+        self.assertEqual(changes['testapp'][0].dependencies, [('otherapp', '0001_initial')])
+
     def test_trim_apps(self):
         """
         Trim does not remove dependencies but does remove unwanted apps.
@@ -2524,6 +2544,14 @@ class MigrationSuggestNameTests(SimpleTestCase):
         suggest_name = migration.suggest_name()
         self.assertIs(suggest_name.startswith('auto_'), True)
 
+    def test_none_name_with_initial_true(self):
+        class Migration(migrations.Migration):
+            initial = True
+            operations = [migrations.RunSQL('SELECT 1 FROM person;')]
+
+        migration = Migration('0001_initial', 'test_app')
+        self.assertEqual(migration.suggest_name(), 'initial')
+
     def test_auto(self):
         migration = migrations.Migration('0001_initial', 'test_app')
         suggest_name = migration.suggest_name()