[1.7.x] Fixed #23071 -- Use last migration's name in dependency to other app

Changed the autodetector to lookup the name of the other app's last
migration in the graph and use that as dependency instead of using
__latest__.

7 files changed, 3 insertions, 59 deletions

diff --git a/tests/migrations/test_autodetector.py b/tests/migrations/test_autodetector.py
index 3a9e348535..3de9e5d6ba 100644
--- a/tests/migrations/test_autodetector.py
+++ b/tests/migrations/test_autodetector.py
@@ -1057,7 +1057,8 @@ class AutodetectorTests(TestCase):
     @override_settings(MIGRATION_MODULES={"migrations": "migrations.test_migrations"})
     def test_last_dependency(self):
         """
-        Tests that a dependency to an app with existing migrations uses __latest__.
+        Tests that a dependency to an app with existing migrations uses the
+        last migration of that app.
         """
         # Load graph
         loader = MigrationLoader(connection)
@@ -1072,4 +1073,4 @@ class AutodetectorTests(TestCase):
         self.assertOperationTypes(changes, 'otherapp', 0, ["CreateModel"])
         self.assertOperationAttributes(changes, 'otherapp', 0, 0, name="Book")
         # Right dependencies?
-        self.assertEqual(changes['otherapp'][0].dependencies, [("migrations", "__latest__")])
+        self.assertEqual(changes['otherapp'][0].dependencies, [("migrations", "0002_second")])
diff --git a/tests/migrations/test_loader.py b/tests/migrations/test_loader.py
index c0f9f1a6dd..68d05d296f 100644
--- a/tests/migrations/test_loader.py
+++ b/tests/migrations/test_loader.py
@@ -122,26 +122,6 @@ class LoaderTests(TestCase):
             ],
         )
 
-    @modify_settings(INSTALLED_APPS={'append': 'basic'})
-    @override_settings(MIGRATION_MODULES={
-        "migrations": "migrations.test_migrations_latest",
-        "basic": "migrations.test_migrations_latest_basic",
-    })
-    def test_latest(self):
-        """
-        Makes sure that __latest__ works correctly.
-        """
-        # Load and test the plan
-        migration_loader = MigrationLoader(connection)
-        self.assertEqual(
-            migration_loader.graph.forwards_plan(("migrations", "0001_initial")),
-            [
-                ("basic", "0001_initial"),
-                ("basic", "0002_second"),
-                ("migrations", "0001_initial"),
-            ],
-        )
-
     @override_settings(MIGRATION_MODULES={
         "migrations": "migrations.test_migrations_first",
         "migrations2": "migrations2.test_migrations_2_first",
diff --git a/tests/migrations/test_migrations_latest/0001_initial.py b/tests/migrations/test_migrations_latest/0001_initial.py
deleted file mode 100644
index e16bb2152d..0000000000
--- a/tests/migrations/test_migrations_latest/0001_initial.py
+++ /dev/null
@@ -1,13 +0,0 @@
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-
-from django.db import migrations
-
-
-class Migration(migrations.Migration):
-
-    dependencies = [
-        ("basic", "__latest__"),
-    ]
-
-    operations = []
diff --git a/tests/migrations/test_migrations_latest/__init__.py b/tests/migrations/test_migrations_latest/__init__.py
deleted file mode 100644
index e69de29bb2..0000000000
--- a/tests/migrations/test_migrations_latest/__init__.py
+++ /dev/null
diff --git a/tests/migrations/test_migrations_latest_basic/0001_initial.py b/tests/migrations/test_migrations_latest_basic/0001_initial.py
deleted file mode 100644
index 4df0594154..0000000000
--- a/tests/migrations/test_migrations_latest_basic/0001_initial.py
+++ /dev/null
@@ -1,11 +0,0 @@
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-
-from django.db import migrations
-
-
-class Migration(migrations.Migration):
-
-    dependencies = []
-
-    operations = []
diff --git a/tests/migrations/test_migrations_latest_basic/0002_second.py b/tests/migrations/test_migrations_latest_basic/0002_second.py
deleted file mode 100644
index 49f5b1966c..0000000000
--- a/tests/migrations/test_migrations_latest_basic/0002_second.py
+++ /dev/null
@@ -1,13 +0,0 @@
-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-
-from django.db import migrations
-
-
-class Migration(migrations.Migration):
-
-    dependencies = [
-        ("basic", "0001_initial"),
-    ]
-
-    operations = []
diff --git a/tests/migrations/test_migrations_latest_basic/__init__.py b/tests/migrations/test_migrations_latest_basic/__init__.py
deleted file mode 100644
index e69de29bb2..0000000000
--- a/tests/migrations/test_migrations_latest_basic/__init__.py
+++ /dev/null