[1.8.x] Refs #24628 -- Added a second test and a docstring comment to avoid regression.

Backport of 5c085ea7b3f3ff10389aeed327e018581791876a from master.

1 files changed, 24 insertions, 0 deletions

diff --git a/tests/migrations/test_executor.py b/tests/migrations/test_executor.py
index 9946dd4503..0eefc32b1f 100644
--- a/tests/migrations/test_executor.py
+++ b/tests/migrations/test_executor.py
@@ -437,6 +437,30 @@ class ExecutorTests(MigrationTestBase):
             recorder.applied_migrations(),
         )
 
+    @override_settings(MIGRATION_MODULES={"migrations": "migrations.test_migrations_squashed"})
+    def test_migrate_marks_replacement_applied_even_if_it_did_nothing(self):
+        """
+        A new squash migration will be marked as applied even if all its
+        replaced migrations were previously already applied.
+
+        Ticket #24628.
+
+        """
+        recorder = MigrationRecorder(connection)
+        # Record all replaced migrations as applied
+        recorder.record_applied("migrations", "0001_initial")
+        recorder.record_applied("migrations", "0002_second")
+        executor = MigrationExecutor(connection)
+        executor.migrate([("migrations", "0001_squashed_0002")])
+
+        # Because 0001 and 0002 are both applied, even though this migrate run
+        # didn't apply anything new, their squashed replacement should be
+        # marked as applied.
+        self.assertIn(
+            ("migrations", "0001_squashed_0002"),
+            recorder.applied_migrations(),
+        )
+
 
 class FakeLoader(object):
     def __init__(self, graph, applied):