[2.1.x] Fixed #29749 -- Made the migrations loader ignore files starting with a tilde or underscore.

Regression in 29150d5da880ac1db15e47052330790cf1b802d2.
Backport of 32fbccab406b680bc0a0a8d39a9b95c3a08bbc5a from master

6 files changed, 13 insertions, 0 deletions

diff --git a/tests/migrations/test_loader.py b/tests/migrations/test_loader.py
index 71d3c9ca36..a7666c5c2d 100644
--- a/tests/migrations/test_loader.py
+++ b/tests/migrations/test_loader.py
@@ -500,6 +500,14 @@ class LoaderTests(TestCase):
         }
         self.assertEqual(plan, expected_plan)
 
+    @override_settings(MIGRATION_MODULES={'migrations': 'migrations.test_migrations_private'})
+    def test_ignore_files(self):
+        """Files prefixed with underscore, tilde, or dot aren't loaded."""
+        loader = MigrationLoader(connection)
+        loader.load_disk()
+        migrations = [name for app, name in loader.disk_migrations if app == 'migrations']
+        self.assertEqual(migrations, ['0001_initial'])
+
 
 class PycLoaderTests(MigrationTestBase):
 
diff --git a/tests/migrations/test_migrations_private/.util.py b/tests/migrations/test_migrations_private/.util.py
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/tests/migrations/test_migrations_private/.util.py
diff --git a/tests/migrations/test_migrations_private/0001_initial.py b/tests/migrations/test_migrations_private/0001_initial.py
new file mode 100644
index 0000000000..bd613aa95e
--- /dev/null
+++ b/tests/migrations/test_migrations_private/0001_initial.py
@@ -0,0 +1,5 @@
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+    pass
diff --git a/tests/migrations/test_migrations_private/__init__.py b/tests/migrations/test_migrations_private/__init__.py
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/tests/migrations/test_migrations_private/__init__.py
diff --git a/tests/migrations/test_migrations_private/_util.py b/tests/migrations/test_migrations_private/_util.py
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/tests/migrations/test_migrations_private/_util.py
diff --git a/tests/migrations/test_migrations_private/~util.py b/tests/migrations/test_migrations_private/~util.py
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/tests/migrations/test_migrations_private/~util.py