Fixed #20603 -- Made the test suite faster.

By avoiding to run syncdb with the full set of test models.

Thanks Anssi for the idea.

tests/multiple_database/tests.py

@@ -1943,6 +1943,12 @@ class SyncOnlyDefaultDatabaseRouter(object):
 
 
 class SyncDBTestCase(TestCase):
+
+    available_apps  = [
+        'multiple_database',
+        'django.contrib.auth',
+        'django.contrib.contenttypes'
+    ]
     multi_db = True
 
     def test_syncdb_to_other_database(self):

tests/swappable_models/tests.py

@@ -13,6 +13,13 @@ from swappable_models.models import Article
 
 
 class SwappableModelTests(TestCase):
+
+    available_apps = [
+        'swappable_models',
+        'django.contrib.auth',
+        'django.contrib.contenttypes',
+    ]
+
     def setUp(self):
         # This test modifies the installed apps, so we need to make sure
         # we're not dealing with a cached app list.

tests/syncdb_signals/tests.py

@@ -55,6 +55,11 @@ signals.pre_syncdb.connect(pre_syncdb_receiver, sender=models)
 
 
 class SyncdbSignalTests(TestCase):
+
+    available_apps = [
+        'syncdb_signals',
+    ]
+
     def test_pre_syncdb_call_time(self):
         self.assertEqual(pre_syncdb_receiver.call_counter, 1)
 

tests/test_runner/tests.py

@@ -9,7 +9,7 @@ from optparse import make_option
 from django.core.exceptions import ImproperlyConfigured
 from django.core.management import call_command
 from django import db
-from django.test import runner, TransactionTestCase, skipUnlessDBFeature
+from django.test import runner, TestCase, TransactionTestCase, skipUnlessDBFeature
 from django.test.testcases import connections_support_transactions
 from django.test.utils import IgnorePendingDeprecationWarningsMixin
 from django.utils import unittest
@@ -240,7 +240,9 @@ class ModulesTestsPackages(IgnorePendingDeprecationWarningsMixin, unittest.TestC
         self.assertRaises(ImportError, get_tests, module)
 
 
-class Sqlite3InMemoryTestDbs(unittest.TestCase):
+class Sqlite3InMemoryTestDbs(TestCase):
+
+    available_apps = []
 
     @unittest.skipUnless(all(db.connections[conn].vendor == 'sqlite' for conn in db.connections),
                          "This is a sqlite-specific issue")