[3.7] bpo-33383: Fix crash in get() of the dbm.ndbm database object. (GH-6630) (GH-6631)

(cherry picked from commit 2e38cc39330bd7f3003652869b644110a97a78d8)

Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/Lib/test/test_dbm_dumb.py b/Lib/test/test_dbm_dumb.py
index fa14238..7f5c09f 100644
--- a/Lib/test/test_dbm_dumb.py
+++ b/Lib/test/test_dbm_dumb.py
@@ -73,6 +73,9 @@ class DumbDBMTestCase(unittest.TestCase):
         f = dumbdbm.open(_fname, 'w')
         self._dict[b'g'] = f[b'g'] = b"indented"
         self.read_helper(f)
+        # setdefault() works as in the dict interface
+        self.assertEqual(f.setdefault(b'xxx', b'foo'), b'foo')
+        self.assertEqual(f[b'xxx'], b'foo')
         f.close()
 
     def test_dumbdbm_read(self):
@@ -85,6 +88,12 @@ class DumbDBMTestCase(unittest.TestCase):
         with self.assertWarnsRegex(DeprecationWarning,
                                    'The database is opened for reading only'):
             del f[b'a']
+        # get() works as in the dict interface
+        self.assertEqual(f.get(b'b'), self._dict[b'b'])
+        self.assertEqual(f.get(b'xxx', b'foo'), b'foo')
+        self.assertIsNone(f.get(b'xxx'))
+        with self.assertRaises(KeyError):
+            f[b'xxx']
         f.close()
 
     def test_dumbdbm_keys(self):