From de41fbb3cf39cf24387ba03e6a6cfb697a789a2d Mon Sep 17 00:00:00 2001
From: Caio Ariede <caio.ariede@gmail.com>
Date: Tue, 11 Aug 2015 01:42:11 -0300
Subject: [PATCH] Fixed #25239 -- Corrected makemigrations numbering if a
 migration has a number-only filename.

---
 django/db/migrations/autodetector.py               |  5 +++--
 tests/migrations/test_commands.py                  | 13 +++++++++++++
 tests/migrations/test_migrations_order/0001.py     | 12 ++++++++++++
 tests/migrations/test_migrations_order/__init__.py |  0
 4 files changed, 28 insertions(+), 2 deletions(-)
 create mode 100644 tests/migrations/test_migrations_order/0001.py
 create mode 100644 tests/migrations/test_migrations_order/__init__.py

diff --git a/django/db/migrations/autodetector.py b/django/db/migrations/autodetector.py
index b20946999f..41830f06ba 100644
--- a/django/db/migrations/autodetector.py
+++ b/django/db/migrations/autodetector.py
@@ -1154,6 +1154,7 @@ class MigrationAutodetector(object):
         Given a migration name, tries to extract a number from the
         beginning of it. If no number found, returns None.
         """
-        if re.match(r"^\d+_", name):
-            return int(name.split("_")[0])
+        match = re.match(r'^\d+', name)
+        if match:
+            return int(match.group())
         return None
diff --git a/tests/migrations/test_commands.py b/tests/migrations/test_commands.py
index 41860e64dd..8ca47aec2d 100644
--- a/tests/migrations/test_commands.py
+++ b/tests/migrations/test_commands.py
@@ -510,6 +510,19 @@ class MakeMigrationsTests(MigrationTestBase):
                     self.assertIn('\\xda\\xd1\\xcd\\xa2\\xd3\\xd0\\xc9', content)  # title.verbose_name
                     self.assertIn('\\u201c\\xd0j\\xe1\\xf1g\\xf3\\u201d', content)  # title.default
 
+    def test_makemigrations_order(self):
+        """
+        makemigrations should recognize number-only migrations (0001.py).
+        """
+        module = 'migrations.test_migrations_order'
+        with self.temporary_migration_module(module=module) as migration_dir:
+            if hasattr(importlib, 'invalidate_caches'):
+                # Python 3 importlib caches os.listdir() on some platforms like
+                # Mac OS X (#23850).
+                importlib.invalidate_caches()
+            call_command('makemigrations', 'migrations', '--empty', '-n', 'a', '-v', '0')
+            self.assertTrue(os.path.exists(os.path.join(migration_dir, '0002_a.py')))
+
     def test_failing_migration(self):
         # If a migration fails to serialize, it shouldn't generate an empty file. #21280
         apps.register_model('migrations', UnserializableModel)
diff --git a/tests/migrations/test_migrations_order/0001.py b/tests/migrations/test_migrations_order/0001.py
new file mode 100644
index 0000000000..402c13e7f6
--- /dev/null
+++ b/tests/migrations/test_migrations_order/0001.py
@@ -0,0 +1,12 @@
+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    initial = True
+
+    operations = [
+    ]
diff --git a/tests/migrations/test_migrations_order/__init__.py b/tests/migrations/test_migrations_order/__init__.py
new file mode 100644
index 0000000000..e69de29bb2