Fixed #17530 - Fixture loading with deferred constraints broken for Postgres for fixtures from multiple dirs/files

Thanks to claudep for the review.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@17372 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/core/management/commands/loaddata.py

@@ -104,6 +104,9 @@ class Command(BaseCommand):
                 app_module_paths.append(app.__file__)
 
         app_fixtures = [os.path.join(os.path.dirname(path), 'fixtures') for path in app_module_paths]
+
+        try:
+            with connection.constraint_checks_disabled():
                 for fixture_label in fixture_labels:
                     parts = fixture_label.split('.')
 
@@ -166,25 +169,24 @@ class Command(BaseCommand):
                                     self.stdout.write("No %s fixture '%s' in %s.\n" % \
                                         (format, fixture_name, humanize(fixture_dir)))
                             else:
+                                try:
                                     if label_found:
-                            fixture.close()
                                         self.stderr.write(self.style.ERROR("Multiple fixtures named '%s' in %s. Aborting.\n" %
                                             (fixture_name, humanize(fixture_dir))))
                                         if commit:
                                             transaction.rollback(using=using)
                                             transaction.leave_transaction_management(using=using)
                                         return
-                        else:
+
                                     fixture_count += 1
                                     objects_in_fixture = 0
                                     loaded_objects_in_fixture = 0
                                     if verbosity >= 2:
                                         self.stdout.write("Installing %s fixture '%s' from %s.\n" % \
                                             (format, fixture_name, humanize(fixture_dir)))
-                            try:
+
                                     objects = serializers.deserialize(format, fixture, using=using)
 
-                                with connection.constraint_checks_disabled():
                                     for obj in objects:
                                         objects_in_fixture += 1
                                         if router.allow_syncdb(using, obj.object.__class__):
@@ -201,29 +203,10 @@ class Command(BaseCommand):
                                                     }
                                                 raise e.__class__, e.__class__(msg), sys.exc_info()[2]
 
-                                # Since we disabled constraint checks, we must manually check for
-                                # any invalid keys that might have been added
-                                table_names = [model._meta.db_table for model in models]
-                                connection.check_constraints(table_names=table_names)
-
                                     loaded_object_count += loaded_objects_in_fixture
                                     fixture_object_count += objects_in_fixture
                                     label_found = True
-                            except (SystemExit, KeyboardInterrupt):
+                                finally:
-                                raise
-                            except Exception:
-                                fixture.close()
-                                if commit:
-                                    transaction.rollback(using=using)
-                                    transaction.leave_transaction_management(using=using)
-                                if show_traceback:
-                                    traceback.print_exc()
-                                else:
-                                    self.stderr.write(
-                                        self.style.ERROR("Problem installing fixture '%s': %s\n" %
-                                             (full_path, ''.join(traceback.format_exception(sys.exc_type,
-                                                 sys.exc_value, sys.exc_traceback)))))
-                                return
                                     fixture.close()
 
                                 # If the fixture we loaded contains 0 objects, assume that an
@@ -237,6 +220,27 @@ class Command(BaseCommand):
                                         transaction.leave_transaction_management(using=using)
                                     return
 
+            # Since we disabled constraint checks, we must manually check for
+            # any invalid keys that might have been added
+            table_names = [model._meta.db_table for model in models]
+            connection.check_constraints(table_names=table_names)
+
+        except (SystemExit, KeyboardInterrupt):
+            raise
+        except Exception:
+            if commit:
+                transaction.rollback(using=using)
+                transaction.leave_transaction_management(using=using)
+            if show_traceback:
+                traceback.print_exc()
+            else:
+                self.stderr.write(
+                    self.style.ERROR("Problem installing fixture '%s': %s\n" %
+                         (full_path, ''.join(traceback.format_exception(sys.exc_type,
+                             sys.exc_value, sys.exc_traceback)))))
+            return
+
+
         # If we found even one object in a fixture, we need to reset the
         # database sequences.
         if loaded_object_count > 0:

tests/regressiontests/fixtures_regress/fixtures_1/forward_ref_1.json

@@ -0,0 +1,10 @@
+[
+    {
+        "pk": 1,
+        "model": "fixtures_regress.book",
+        "fields": {
+            "name": "Cryptonomicon",
+            "author": 4
+        }
+    }
+]

tests/regressiontests/fixtures_regress/fixtures_2/forward_ref_2.json

@@ -0,0 +1,9 @@
+[
+    {
+        "pk": "4",
+        "model": "fixtures_regress.person",
+        "fields": {
+            "name": "Neal Stephenson"
+        }
+    }
+]

tests/regressiontests/fixtures_regress/tests.py

@@ -16,6 +16,7 @@ from django.db import transaction
 from django.db.models import signals
 from django.test import (TestCase, TransactionTestCase, skipIfDBFeature,
     skipUnlessDBFeature)
+from django.test.utils import override_settings
 
 from .models import (Animal, Stuff, Absolute, Parent, Child, Article, Widget,
     Store, Person, Book, NKChild, RefToNKChild, Circle1, Circle2, Circle3,
@@ -390,6 +391,25 @@ class TestFixtures(TestCase):
             stderr.getvalue().startswith('Problem installing fixture')
         )
 
+    _cur_dir = os.path.dirname(os.path.abspath(__file__))
+
+    @override_settings(FIXTURE_DIRS=[os.path.join(_cur_dir, 'fixtures_1'),
+                                     os.path.join(_cur_dir, 'fixtures_2')])
+    def test_loaddata_forward_refs_split_fixtures(self):
+        """
+        Regression for #17530 - should be able to cope with forward references
+        when the fixtures are not in the same files or directories.
+        """
+        management.call_command(
+            'loaddata',
+            'forward_ref_1.json',
+            'forward_ref_2.json',
+            verbosity=0,
+            commit=False
+        )
+        self.assertEqual(Book.objects.all()[0].id, 1)
+        self.assertEqual(Person.objects.all()[0].id, 4)
+
     def test_loaddata_no_fixture_specified(self):
         """
         Regression for #7043 - Error is quickly reported when no fixtures is provided in the command line.