[2.1.x] Fixed #29613 -- Fixed --keepdb on PostgreSQL if the database exists and the user can't create databases.

Regression in e776dd2db677d58dcb50aea20d3bb191537df25b.

Thanks Tim Graham for the review.
Backport of 1a9cbf41a130def83a7e384955544d08be0fc148 from master

1 files changed, 10 insertions, 3 deletions

diff --git a/tests/backends/postgresql/test_creation.py b/tests/backends/postgresql/test_creation.py
index 9f51d5e6b2..7d6f319a80 100644
--- a/tests/backends/postgresql/test_creation.py
+++ b/tests/backends/postgresql/test_creation.py
@@ -89,7 +89,14 @@ class DatabaseCreationTests(SimpleTestCase):
             creation._create_test_db(verbosity=0, autoclobber=False, keepdb=True)
         # Simulate test database creation raising unexpected error
         with self.patch_test_db_creation(self._execute_raise_permission_denied):
-            with self.assertRaises(SystemExit):
-                creation._create_test_db(verbosity=0, autoclobber=False, keepdb=False)
-            with self.assertRaises(SystemExit):
+            with mock.patch.object(DatabaseCreation, '_database_exists', return_value=False):
+                with self.assertRaises(SystemExit):
+                    creation._create_test_db(verbosity=0, autoclobber=False, keepdb=False)
+                with self.assertRaises(SystemExit):
+                    creation._create_test_db(verbosity=0, autoclobber=False, keepdb=True)
+        # Simulate test database creation raising "insufficient privileges".
+        # An error shouldn't appear when keepdb is on and the database already
+        # exists.
+        with self.patch_test_db_creation(self._execute_raise_permission_denied):
+            with mock.patch.object(DatabaseCreation, '_database_exists', return_value=True):
                 creation._create_test_db(verbosity=0, autoclobber=False, keepdb=True)