Fixed #22853: Swapped models are now ignored for migration operations.

django/db/migrations/operations/base.py

@@ -1,4 +1,5 @@
 from __future__ import unicode_literals
+from django.db import router
 
 
 class Operation(object):
@@ -97,6 +98,17 @@ class Operation(object):
         """
         return self.references_model(model_name, app_label)
 
+    def allowed_to_migrate(self, connection_alias, model):
+        """
+        Returns if we're allowed to migrate the model. Checks the router,
+        if it's a proxy, and if it's swapped out.
+        """
+        return (
+            router.allow_migrate(connection_alias, model) and
+            not model._meta.proxy and
+            not model._meta.swapped
+        )
+
     def __repr__(self):
         return "<%s %s%s>" % (
             self.__class__.__name__,

django/db/migrations/operations/fields.py

@@ -1,6 +1,5 @@
 from __future__ import unicode_literals
 
-from django.db import router
 from django.db.models.fields import NOT_PROVIDED
 from django.utils import six
 from .base import Operation
@@ -29,7 +28,7 @@ class AddField(Operation):
     def database_forwards(self, app_label, schema_editor, from_state, to_state):
         from_model = from_state.render().get_model(app_label, self.model_name)
         to_model = to_state.render().get_model(app_label, self.model_name)
-        if router.allow_migrate(schema_editor.connection.alias, to_model):
+        if self.allowed_to_migrate(schema_editor.connection.alias, to_model):
             field = to_model._meta.get_field_by_name(self.name)[0]
             if not self.preserve_default:
                 field.default = self.field.default
@@ -42,7 +41,7 @@ class AddField(Operation):
 
     def database_backwards(self, app_label, schema_editor, from_state, to_state):
         from_model = from_state.render().get_model(app_label, self.model_name)
-        if router.allow_migrate(schema_editor.connection.alias, from_model):
+        if self.allowed_to_migrate(schema_editor.connection.alias, from_model):
             schema_editor.remove_field(from_model, from_model._meta.get_field_by_name(self.name)[0])
 
     def describe(self):
@@ -81,13 +80,13 @@ class RemoveField(Operation):
 
     def database_forwards(self, app_label, schema_editor, from_state, to_state):
         from_model = from_state.render().get_model(app_label, self.model_name)
-        if router.allow_migrate(schema_editor.connection.alias, from_model):
+        if self.allowed_to_migrate(schema_editor.connection.alias, from_model):
             schema_editor.remove_field(from_model, from_model._meta.get_field_by_name(self.name)[0])
 
     def database_backwards(self, app_label, schema_editor, from_state, to_state):
         from_model = from_state.render().get_model(app_label, self.model_name)
         to_model = to_state.render().get_model(app_label, self.model_name)
-        if router.allow_migrate(schema_editor.connection.alias, to_model):
+        if self.allowed_to_migrate(schema_editor.connection.alias, to_model):
             schema_editor.add_field(from_model, to_model._meta.get_field_by_name(self.name)[0])
 
     def describe(self):
@@ -118,7 +117,7 @@ class AlterField(Operation):
     def database_forwards(self, app_label, schema_editor, from_state, to_state):
         from_model = from_state.render().get_model(app_label, self.model_name)
         to_model = to_state.render().get_model(app_label, self.model_name)
-        if router.allow_migrate(schema_editor.connection.alias, to_model):
+        if self.allowed_to_migrate(schema_editor.connection.alias, to_model):
             from_field = from_model._meta.get_field_by_name(self.name)[0]
             to_field = to_model._meta.get_field_by_name(self.name)[0]
             # If the field is a relatedfield with an unresolved rel.to, just
@@ -170,7 +169,7 @@ class RenameField(Operation):
     def database_forwards(self, app_label, schema_editor, from_state, to_state):
         from_model = from_state.render().get_model(app_label, self.model_name)
         to_model = to_state.render().get_model(app_label, self.model_name)
-        if router.allow_migrate(schema_editor.connection.alias, to_model):
+        if self.allowed_to_migrate(schema_editor.connection.alias, to_model):
             schema_editor.alter_field(
                 from_model,
                 from_model._meta.get_field_by_name(self.old_name)[0],
@@ -180,7 +179,7 @@ class RenameField(Operation):
     def database_backwards(self, app_label, schema_editor, from_state, to_state):
         from_model = from_state.render().get_model(app_label, self.model_name)
         to_model = to_state.render().get_model(app_label, self.model_name)
-        if router.allow_migrate(schema_editor.connection.alias, to_model):
+        if self.allowed_to_migrate(schema_editor.connection.alias, to_model):
             schema_editor.alter_field(
                 from_model,
                 from_model._meta.get_field_by_name(self.new_name)[0],

django/db/migrations/operations/models.py

@@ -1,6 +1,6 @@
 from __future__ import unicode_literals
 
-from django.db import models, router
+from django.db import models
 from django.db.models.options import normalize_together
 from django.db.migrations.state import ModelState
 from django.db.migrations.operations.base import Operation
@@ -32,13 +32,13 @@ class CreateModel(Operation):
     def database_forwards(self, app_label, schema_editor, from_state, to_state):
         apps = to_state.render()
         model = apps.get_model(app_label, self.name)
-        if router.allow_migrate(schema_editor.connection.alias, model) and not model._meta.proxy:
+        if self.allowed_to_migrate(schema_editor.connection.alias, model):
             schema_editor.create_model(model)
 
     def database_backwards(self, app_label, schema_editor, from_state, to_state):
         apps = from_state.render()
         model = apps.get_model(app_label, self.name)
-        if router.allow_migrate(schema_editor.connection.alias, model) and not model._meta.proxy:
+        if self.allowed_to_migrate(schema_editor.connection.alias, model):
             schema_editor.delete_model(model)
 
     def describe(self):
@@ -85,13 +85,13 @@ class DeleteModel(Operation):
     def database_forwards(self, app_label, schema_editor, from_state, to_state):
         apps = from_state.render()
         model = apps.get_model(app_label, self.name)
-        if router.allow_migrate(schema_editor.connection.alias, model) and not model._meta.proxy:
+        if self.allowed_to_migrate(schema_editor.connection.alias, model):
             schema_editor.delete_model(model)
 
     def database_backwards(self, app_label, schema_editor, from_state, to_state):
         apps = to_state.render()
         model = apps.get_model(app_label, self.name)
-        if router.allow_migrate(schema_editor.connection.alias, model) and not model._meta.proxy:
+        if self.allowed_to_migrate(schema_editor.connection.alias, model):
             schema_editor.create_model(model)
 
     def references_model(self, name, app_label=None):
@@ -141,7 +141,7 @@ class RenameModel(Operation):
         new_apps = to_state.render()
         old_model = old_apps.get_model(app_label, self.old_name)
         new_model = new_apps.get_model(app_label, self.new_name)
-        if router.allow_migrate(schema_editor.connection.alias, new_model):
+        if self.allowed_to_migrate(schema_editor.connection.alias, new_model):
             # Move the main table
             schema_editor.alter_db_table(
                 new_model,
@@ -194,7 +194,7 @@ class AlterModelTable(Operation):
         new_apps = to_state.render()
         old_model = old_apps.get_model(app_label, self.name)
         new_model = new_apps.get_model(app_label, self.name)
-        if router.allow_migrate(schema_editor.connection.alias, new_model):
+        if self.allowed_to_migrate(schema_editor.connection.alias, new_model):
             schema_editor.alter_db_table(
                 new_model,
                 old_model._meta.db_table,
@@ -231,7 +231,7 @@ class AlterUniqueTogether(Operation):
         new_apps = to_state.render()
         old_model = old_apps.get_model(app_label, self.name)
         new_model = new_apps.get_model(app_label, self.name)
-        if router.allow_migrate(schema_editor.connection.alias, new_model):
+        if self.allowed_to_migrate(schema_editor.connection.alias, new_model):
             schema_editor.alter_unique_together(
                 new_model,
                 getattr(old_model._meta, "unique_together", set()),
@@ -268,7 +268,7 @@ class AlterIndexTogether(Operation):
         new_apps = to_state.render()
         old_model = old_apps.get_model(app_label, self.name)
         new_model = new_apps.get_model(app_label, self.name)
-        if router.allow_migrate(schema_editor.connection.alias, new_model):
+        if self.allowed_to_migrate(schema_editor.connection.alias, new_model):
             schema_editor.alter_index_together(
                 new_model,
                 getattr(old_model._meta, "index_together", set()),
@@ -301,7 +301,7 @@ class AlterOrderWithRespectTo(Operation):
     def database_forwards(self, app_label, schema_editor, from_state, to_state):
         from_model = from_state.render().get_model(app_label, self.name)
         to_model = to_state.render().get_model(app_label, self.name)
-        if router.allow_migrate(schema_editor.connection.alias, to_model):
+        if self.allowed_to_migrate(schema_editor.connection.alias, to_model):
             # Remove a field if we need to
             if from_model._meta.order_with_respect_to and not to_model._meta.order_with_respect_to:
                 schema_editor.remove_field(from_model, from_model._meta.get_field_by_name("_order")[0])

docs/ref/settings.txt

@@ -2374,6 +2374,12 @@ Default: 'auth.User'
 
 The model to use to represent a User. See :ref:`auth-custom-user`.
 
+.. warning::
+    You cannot change the AUTH_USER_MODEL setting during the lifetime of
+    a project (i.e. once you have made and migrated models that depend on it)
+    without serious effort. It is intended to be set at the project start.
+    See :ref:`auth-custom-user` for more details.
+
 .. setting:: LOGIN_REDIRECT_URL
 
 LOGIN_REDIRECT_URL

docs/topics/auth/customizing.txt

@@ -389,7 +389,8 @@ use as your User model.
 
    Changing this setting after you have tables created is not supported
    by :djadmin:`makemigrations` and will result in you having to manually
-   write a set of migrations to fix your schema.
+   fix your schema, port your data from the old user table, and possibly
+   manually reapply some migrations.
 
 Referencing the User model
 --------------------------

tests/migrations/test_operations.py

@@ -8,6 +8,7 @@ except ImportError:
     sqlparse = None
 
 from django import test
+from django.test import override_settings
 from django.db import connection, migrations, models, router
 from django.db.migrations.migration import Migration
 from django.db.migrations.state import ProjectState
@@ -18,11 +19,9 @@ from django.db.utils import IntegrityError, DatabaseError
 from .test_base import MigrationTestBase
 
 
-class OperationTests(MigrationTestBase):
+class OperationTestBase(MigrationTestBase):
     """
-    Tests running the operations and making sure they do what they say they do.
+    Common functions to help test operations.
-    Each test looks at their state changing, and then their database operation -
-    both forwards and backwards.
     """
 
     def apply_operations(self, app_label, project_state, operations):
@@ -37,6 +36,16 @@ class OperationTests(MigrationTestBase):
         with connection.schema_editor() as editor:
             return migration.unapply(project_state, editor)
 
+    def make_test_state(self, app_label, operation, **kwargs):
+        """
+        Makes a test state using set_up_test_model and returns the
+        original state and the state after the migration is applied.
+        """
+        project_state = self.set_up_test_model(app_label, **kwargs)
+        new_state = project_state.clone()
+        operation.state_forwards(app_label, new_state)
+        return project_state, new_state
+
     def set_up_test_model(self, app_label, second_model=False, third_model=False, related_model=False, mti_model=False, proxy_model=False):
         """
         Creates a test model state and database table.
@@ -74,6 +83,9 @@ class OperationTests(MigrationTestBase):
                 ("pink", models.IntegerField(default=3)),
                 ("weight", models.FloatField()),
             ],
+            options = {
+                "swappable": "TEST_SWAP_MODEL",
+            },
         )]
         if second_model:
             operations.append(migrations.CreateModel(
@@ -122,6 +134,15 @@ class OperationTests(MigrationTestBase):
 
         return self.apply_operations(app_label, ProjectState(), operations)
 
+
+class OperationTests(OperationTestBase):
+    """
+    Tests running the operations and making sure they do what they say they do.
+    Each test looks at their state changing, and then their database operation -
+    both forwards and backwards.
+    """
+
+
     def test_create_model(self):
         """
         Tests the CreateModel operation.
@@ -382,15 +403,13 @@ class OperationTests(MigrationTestBase):
         """
         Tests the AddField operation.
         """
-        project_state = self.set_up_test_model("test_adfl")
         # Test the state alteration
         operation = migrations.AddField(
             "Pony",
             "height",
             models.FloatField(null=True, default=5),
         )
-        new_state = project_state.clone()
+        project_state, new_state = self.make_test_state("test_adfl", operation)
-        operation.state_forwards("test_adfl", new_state)
         self.assertEqual(len(new_state.models["test_adfl", "pony"].fields), 4)
         field = [
             f for n, f in new_state.models["test_adfl", "pony"].fields
@@ -1117,3 +1136,87 @@ class MultiDBOperationTests(MigrationTestBase):
         with connection.schema_editor() as editor:
             operation.database_backwards("test_crmo", editor, new_state, project_state)
         self.assertTableNotExists("test_crmo_pony")
+
+
+class SwappableOperationTests(OperationTestBase):
+    """
+    Tests that key operations ignore swappable models
+    (we don't want to replicate all of them here, as the functionality
+    is in a common base class anyway)
+    """
+
+    available_apps = [
+        "migrations",
+        "django.contrib.auth",
+    ]
+
+    @override_settings(TEST_SWAP_MODEL="migrations.SomeFakeModel")
+    def test_create_ignore_swapped(self):
+        """
+        Tests that the CreateTable operation ignores swapped models.
+        """
+        operation = migrations.CreateModel(
+            "Pony",
+            [
+                ("id", models.AutoField(primary_key=True)),
+                ("pink", models.IntegerField(default=1)),
+            ],
+            options = {
+                "swappable": "TEST_SWAP_MODEL",
+            },
+        )
+        # Test the state alteration (it should still be there!)
+        project_state = ProjectState()
+        new_state = project_state.clone()
+        operation.state_forwards("test_crigsw", new_state)
+        self.assertEqual(new_state.models["test_crigsw", "pony"].name, "Pony")
+        self.assertEqual(len(new_state.models["test_crigsw", "pony"].fields), 2)
+        # Test the database alteration
+        self.assertTableNotExists("test_crigsw_pony")
+        with connection.schema_editor() as editor:
+            operation.database_forwards("test_crigsw", editor, project_state, new_state)
+        self.assertTableNotExists("test_crigsw_pony")
+        # And test reversal
+        with connection.schema_editor() as editor:
+            operation.database_backwards("test_crigsw", editor, new_state, project_state)
+        self.assertTableNotExists("test_crigsw_pony")
+
+    @override_settings(TEST_SWAP_MODEL="migrations.SomeFakeModel")
+    def test_delete_ignore_swapped(self):
+        """
+        Tests the DeleteModel operation ignores swapped models.
+        """
+        operation = migrations.DeleteModel("Pony")
+        project_state, new_state = self.make_test_state("test_dligsw", operation)
+        # Test the database alteration
+        self.assertTableNotExists("test_dligsw_pony")
+        with connection.schema_editor() as editor:
+            operation.database_forwards("test_dligsw", editor, project_state, new_state)
+        self.assertTableNotExists("test_dligsw_pony")
+        # And test reversal
+        with connection.schema_editor() as editor:
+            operation.database_backwards("test_dligsw", editor, new_state, project_state)
+        self.assertTableNotExists("test_dligsw_pony")
+
+    @override_settings(TEST_SWAP_MODEL="migrations.SomeFakeModel")
+    def test_add_field_ignore_swapped(self):
+        """
+        Tests the AddField operation.
+        """
+        # Test the state alteration
+        operation = migrations.AddField(
+            "Pony",
+            "height",
+            models.FloatField(null=True, default=5),
+        )
+        project_state, new_state = self.make_test_state("test_adfligsw", operation)
+        # Test the database alteration
+        self.assertTableNotExists("test_adfligsw_pont")
+        self.assertColumnNotExists("test_adfligsw_pony", "height")
+        with connection.schema_editor() as editor:
+            operation.database_forwards("test_adfligsw", editor, project_state, new_state)
+        self.assertColumnNotExists("test_adfligsw_pony", "height")
+        # And test reversal
+        with connection.schema_editor() as editor:
+            operation.database_backwards("test_adfligsw", editor, new_state, project_state)
+        self.assertColumnNotExists("test_adfligsw_pony", "height")