From 482ee63b6f320cd4a834cb46fc651877bd2f2e28 Mon Sep 17 00:00:00 2001
From: David Wobrock <david.wobrock@gmail.com>
Date: Tue, 4 Jan 2022 06:24:03 +0100
Subject: [PATCH] Fixed #33402 -- Optimized multiple AlterFooTogether
 operations.

---
 django/db/migrations/operations/models.py | 13 +++++++-
 tests/migrations/test_autodetector.py     | 38 +++++------------------
 2 files changed, 19 insertions(+), 32 deletions(-)

diff --git a/django/db/migrations/operations/models.py b/django/db/migrations/operations/models.py
index c120f5d32d..01c44a9a26 100644
--- a/django/db/migrations/operations/models.py
+++ b/django/db/migrations/operations/models.py
@@ -34,9 +34,12 @@ class ModelOperation(Operation):
     def reduce(self, operation, app_label):
         return (
             super().reduce(operation, app_label) or
-            not operation.references_model(self.name, app_label)
+            self.can_reduce_through(operation, app_label)
         )
 
+    def can_reduce_through(self, operation, app_label):
+        return not operation.references_model(self.name, app_label)
+
 
 class CreateModel(ModelOperation):
     """Create a model's table."""
@@ -528,6 +531,14 @@ class AlterTogetherOptionOperation(ModelOptionOperation):
     def migration_name_fragment(self):
         return 'alter_%s_%s' % (self.name_lower, self.option_name)
 
+    def can_reduce_through(self, operation, app_label):
+        return (
+            super().can_reduce_through(operation, app_label) or (
+                isinstance(operation, AlterTogetherOptionOperation) and
+                type(operation) is not type(self)
+            )
+        )
+
 
 class AlterUniqueTogether(AlterTogetherOptionOperation):
     """
diff --git a/tests/migrations/test_autodetector.py b/tests/migrations/test_autodetector.py
index d25b14cedb..bb37af24e3 100644
--- a/tests/migrations/test_autodetector.py
+++ b/tests/migrations/test_autodetector.py
@@ -1573,21 +1573,13 @@ class AutodetectorTests(TestCase):
         self.assertOperationTypes(changes, 'otherapp', 0, [
             'AlterUniqueTogether',
             'AlterIndexTogether',
-            'AlterUniqueTogether',
-            'AlterIndexTogether',
         ])
         self.assertOperationAttributes(
-            changes, 'otherapp', 0, 0, name='book', unique_together=set(),
-        )
-        self.assertOperationAttributes(
-            changes, 'otherapp', 0, 1, name='book', index_together=set(),
-        )
-        self.assertOperationAttributes(
-            changes, 'otherapp', 0, 2, name='book',
+            changes, 'otherapp', 0, 0, name='book',
             unique_together={('title', 'author')},
         )
         self.assertOperationAttributes(
-            changes, 'otherapp', 0, 3, name='book',
+            changes, 'otherapp', 0, 1, name='book',
             index_together={('title', 'author')},
         )
 
@@ -1637,28 +1629,20 @@ class AutodetectorTests(TestCase):
         # Right number/type of migrations?
         self.assertNumberMigrations(changes, "otherapp", 1)
         self.assertOperationTypes(changes, 'otherapp', 0, [
-            'AlterUniqueTogether',
-            'AlterIndexTogether',
             'AlterUniqueTogether',
             'AlterIndexTogether',
             'RemoveField',
         ])
         self.assertOperationAttributes(
-            changes, 'otherapp', 0, 0, name='book', unique_together=set(),
-        )
-        self.assertOperationAttributes(
-            changes, 'otherapp', 0, 1, name='book', index_together=set(),
-        )
-        self.assertOperationAttributes(
-            changes, 'otherapp', 0, 2, name='book',
+            changes, 'otherapp', 0, 0, name='book',
             unique_together={('author', 'title')},
         )
         self.assertOperationAttributes(
-            changes, 'otherapp', 0, 3, name='book',
+            changes, 'otherapp', 0, 1, name='book',
             index_together={('author', 'title')},
         )
         self.assertOperationAttributes(
-            changes, 'otherapp', 0, 4, model_name='book', name='newfield',
+            changes, 'otherapp', 0, 2, model_name='book', name='newfield',
         )
 
     def test_alter_field_and_foo_together(self):
@@ -1744,21 +1728,13 @@ class AutodetectorTests(TestCase):
             'RenameField',
             'AlterUniqueTogether',
             'AlterIndexTogether',
-            'AlterUniqueTogether',
-            'AlterIndexTogether',
         ])
         self.assertOperationAttributes(
-            changes, 'otherapp', 0, 1, name='book', unique_together=set(),
-        )
-        self.assertOperationAttributes(
-            changes, 'otherapp', 0, 2, name='book', index_together=set(),
-        )
-        self.assertOperationAttributes(
-            changes, 'otherapp', 0, 3, name='book',
+            changes, 'otherapp', 0, 1, name='book',
             unique_together={('title', 'newfield2')},
         )
         self.assertOperationAttributes(
-            changes, 'otherapp', 0, 4, name='book',
+            changes, 'otherapp', 0, 2, name='book',
             index_together={('title', 'newfield2')},
         )