#3664: The pickle module could segfault if a Pickler instance is not correctly initialized:

when a subclass forgets to call the base __init__ method,
or when __init__ is called a second time with invalid parameters

Patch by Alexandre Vassalotti.

1 files changed, 14 insertions, 0 deletions

diff --git a/Lib/test/pickletester.py b/Lib/test/pickletester.py
index a622145..4c301ad 100644
--- a/Lib/test/pickletester.py
+++ b/Lib/test/pickletester.py
@@ -996,6 +996,20 @@ class AbstractPickleModuleTests(unittest.TestCase):
         pickle.Pickler(f, -1)
         pickle.Pickler(f, protocol=-1)
 
+    def test_bad_init(self):
+        # Test issue3664 (pickle can segfault from a badly initialized Pickler).
+        from io import BytesIO
+        # Override initialization without calling __init__() of the superclass.
+        class BadPickler(pickle.Pickler):
+            def __init__(self): pass
+
+        class BadUnpickler(pickle.Unpickler):
+            def __init__(self): pass
+
+        self.assertRaises(pickle.PicklingError, BadPickler().dump, 0)
+        self.assertRaises(pickle.UnpicklingError, BadUnpickler().load)
+
+
 class AbstractPersistentPicklerTests(unittest.TestCase):
 
     # This class defines persistent_id() and persistent_load()