Fixed #19806 -- Ensure that content types and permissions aren't created for swapped models.

Thanks to rizumu for the report.

django/contrib/contenttypes/management.py

@@ -5,6 +5,7 @@ from django.utils.encoding import smart_text
 from django.utils import six
 from django.utils.six.moves import input
 
+
 def update_contenttypes(app, created_models, verbosity=2, db=DEFAULT_DB_ALIAS, **kwargs):
     """
     Creates content types for models in the given app, removing any model
@@ -77,6 +78,7 @@ If you're unsure, answer 'no'.
             if verbosity >= 2:
                 print("Stale content types remain.")
 
+
 def update_all_contenttypes(verbosity=2, **kwargs):
     for app in get_apps():
         update_contenttypes(app, None, verbosity, **kwargs)

django/core/management/validation.py

@@ -35,7 +35,10 @@ def get_validation_errors(outfile, app=None):
     for (app_name, error) in get_app_errors().items():
         e.add(app_name, error)
 
-    for cls in models.get_models(app):
+    inc = set(models.get_models(app, include_swapped=True))
+    no_inc = set(models.get_models(app))
+
+    for cls in models.get_models(app, include_swapped=True):
         opts = cls._meta
 
         # Check swappable attribute.
@@ -138,16 +141,17 @@ def get_validation_errors(outfile, app=None):
             # fields, m2m fields, m2m related objects or related objects
             if f.rel:
                 if f.rel.to not in models.get_models():
+                    # If the related model is swapped, provide a hint;
+                    # otherwise, the model just hasn't been installed.
+                    if not isinstance(f.rel.to, six.string_types) and f.rel.to._meta.swapped:
+                        e.add(opts, "'%s' defines a relation with the model '%s.%s', which has been swapped out. Update the relation to point at settings.%s." % (f.name, f.rel.to._meta.app_label, f.rel.to._meta.object_name, f.rel.to._meta.swappable))
+                    else:
                         e.add(opts, "'%s' has a relation with model %s, which has either not been installed or is abstract." % (f.name, f.rel.to))
                 # it is a string and we could not find the model it refers to
                 # so skip the next section
                 if isinstance(f.rel.to, six.string_types):
                     continue
 
-                # Make sure the model we're related hasn't been swapped out
-                if f.rel.to._meta.swapped:
-                    e.add(opts, "'%s' defines a relation with the model '%s.%s', which has been swapped out. Update the relation to point at settings.%s." % (f.name, f.rel.to._meta.app_label, f.rel.to._meta.object_name, f.rel.to._meta.swappable))
-
                 # Make sure the related field specified by a ForeignKey is unique
                 if not f.rel.to._meta.get_field(f.rel.field_name).unique:
                     e.add(opts, "Field '%s' under model '%s' must have a unique=True constraint." % (f.rel.field_name, f.rel.to.__name__))
@@ -184,16 +188,18 @@ def get_validation_errors(outfile, app=None):
             # existing fields, m2m fields, m2m related objects or related
             # objects
             if f.rel.to not in models.get_models():
+                # If the related model is swapped, provide a hint;
+                # otherwise, the model just hasn't been installed.
+                if not isinstance(f.rel.to, six.string_types) and f.rel.to._meta.swapped:
+                    e.add(opts, "'%s' defines a relation with the model '%s.%s', which has been swapped out. Update the relation to point at settings.%s." % (f.name, f.rel.to._meta.app_label, f.rel.to._meta.object_name, f.rel.to._meta.swappable))
+                else:
                     e.add(opts, "'%s' has an m2m relation with model %s, which has either not been installed or is abstract." % (f.name, f.rel.to))
+
                 # it is a string and we could not find the model it refers to
                 # so skip the next section
                 if isinstance(f.rel.to, six.string_types):
                     continue
 
-            # Make sure the model we're related hasn't been swapped out
-            if f.rel.to._meta.swapped:
-                e.add(opts, "'%s' defines a relation with the model '%s.%s', which has been swapped out. Update the relation to point at settings.%s." % (f.name, f.rel.to._meta.app_label, f.rel.to._meta.object_name, f.rel.to._meta.swappable))
-
             # Check that the field is not set to unique.  ManyToManyFields do not support unique.
             if f.unique:
                 e.add(opts, "ManyToManyFields cannot be unique.  Remove the unique argument on '%s'." % f.name)

django/db/models/loading.py

@@ -167,7 +167,7 @@ class AppCache(object):
 
     def get_models(self, app_mod=None,
                    include_auto_created=False, include_deferred=False,
-                   only_installed=True):
+                   only_installed=True, include_swapped=False):
         """
         Given a module containing models, returns a list of the models.
         Otherwise returns a list of all installed models.
@@ -179,8 +179,16 @@ class AppCache(object):
         By default, models created to satisfy deferred attribute
         queries are *not* included in the list of models. However, if
         you specify include_deferred, they will be.
+
+        By default, models that aren't part of installed apps will *not*
+        be included in the list of models. However, if you specify
+        only_installed=False, they will be.
+
+        By default, models that have been swapped out will *not* be
+        included in the list of models. However, if you specify
+        include_swapped, they will be.
         """
-        cache_key = (app_mod, include_auto_created, include_deferred, only_installed)
+        cache_key = (app_mod, include_auto_created, include_deferred, only_installed, include_swapped)
         try:
             return self._get_models_cache[cache_key]
         except KeyError:
@@ -203,7 +211,8 @@ class AppCache(object):
             model_list.extend(
                 model for model in app.values()
                 if ((not model._deferred or include_deferred) and
-                    (not model._meta.auto_created or include_auto_created))
+                    (not model._meta.auto_created or include_auto_created) and
+                    (not model._meta.swapped or include_swapped))
             )
         self._get_models_cache[cache_key] = model_list
         return model_list

tests/regressiontests/swappable_models/models.py

@@ -0,0 +1,15 @@
+from django.db import models
+
+
+class Article(models.Model):
+    title =  models.CharField(max_length=100)
+    publication_date = models.DateField()
+
+    class Meta:
+        swappable = 'TEST_ARTICLE_MODEL'
+
+
+class AlternateArticle(models.Model):
+    title =  models.CharField(max_length=100)
+    publication_date = models.DateField()
+    byline = models.CharField(max_length=100)

tests/regressiontests/swappable_models/tests.py

@@ -0,0 +1,46 @@
+from __future__ import absolute_import, unicode_literals
+
+from django.utils.six import StringIO
+
+from django.contrib.auth.models import Permission
+from django.contrib.contenttypes.models import ContentType
+from django.core import management
+from django.db.models.loading import cache
+from django.test import TestCase
+from django.test.utils import override_settings
+
+
+class SwappableModelTests(TestCase):
+    def setUp(self):
+        # This test modifies the installed apps, so we need to make sure
+        # we're not dealing with a cached app list.
+        cache._get_models_cache.clear()
+
+    def tearDown(self):
+        # By fiddling with swappable models, we alter the installed models
+        # cache, so flush it to make sure there are no side effects.
+        cache._get_models_cache.clear()
+
+    @override_settings(TEST_ARTICLE_MODEL='swappable_models.AlternateArticle')
+    def test_generated_data(self):
+        "Permissions and content types are not created for a swapped model"
+
+        # Delete all permissions and content_types
+        Permission.objects.all().delete()
+        ContentType.objects.all().delete()
+
+        # Re-run syncdb. This will re-build the permissions and content types.
+        new_io = StringIO()
+        management.call_command('syncdb', load_initial_data=False, interactive=False, stdout=new_io)
+
+        # Check that content types and permissions exist for the swapped model,
+        # but not for the swappable model.
+        apps_models = [(p.content_type.app_label, p.content_type.model)
+                       for p in Permission.objects.all()]
+        self.assertIn(('swappable_models', 'alternatearticle'), apps_models)
+        self.assertNotIn(('swappable_models', 'article'), apps_models)
+
+        apps_models = [(ct.app_label, ct.model)
+                       for ct in ContentType.objects.all()]
+        self.assertIn(('swappable_models', 'alternatearticle'), apps_models)
+        self.assertNotIn(('swappable_models', 'article'), apps_models)