Fixed #28386 -- Made operations within non-atomic migrations honor the operation's atomic flag when migrating backwards.

1 files changed, 8 insertions, 0 deletions

diff --git a/tests/migrations/test_executor.py b/tests/migrations/test_executor.py
index d6cc802149..fdbc724faf 100644
--- a/tests/migrations/test_executor.py
+++ b/tests/migrations/test_executor.py
@@ -126,6 +126,14 @@ class ExecutorTests(MigrationTestBase):
         migrations_apps = executor.loader.project_state(("migrations", "0001_initial")).apps
         Editor = migrations_apps.get_model("migrations", "Editor")
         self.assertFalse(Editor.objects.exists())
+        # Record previous migration as successful.
+        executor.migrate([("migrations", "0001_initial")], fake=True)
+        # Rebuild the graph to reflect the new DB state.
+        executor.loader.build_graph()
+        # Migrating backwards is also atomic.
+        with self.assertRaisesMessage(RuntimeError, "Abort migration"):
+            executor.migrate([("migrations", None)])
+        self.assertFalse(Editor.objects.exists())
 
     @override_settings(MIGRATION_MODULES={
         "migrations": "migrations.test_migrations",