bpo-43907: add missing memoize call in pure python pickling of bytearray (GH-25501)
diff --git a/Lib/pickle.py b/Lib/pickle.py
index e63a8b6..5ab312f 100644
--- a/Lib/pickle.py
+++ b/Lib/pickle.py
@@ -818,6 +818,7 @@ def save_bytearray(self, obj):
self._write_large_bytes(BYTEARRAY8 + pack("<Q", n), obj)
else:
self.write(BYTEARRAY8 + pack("<Q", n) + obj)
+ self.memoize(obj)
dispatch[bytearray] = save_bytearray
if _HAVE_PICKLE_BUFFER:
diff --git a/Lib/test/pickletester.py b/Lib/test/pickletester.py
index fd05e7a..8e01d31 100644
--- a/Lib/test/pickletester.py
+++ b/Lib/test/pickletester.py
@@ -1853,6 +1853,14 @@ def test_bytearray(self):
self.assertNotIn(b'bytearray', p)
self.assertTrue(opcode_in_pickle(pickle.BYTEARRAY8, p))
+ def test_bytearray_memoization_bug(self):
+ for proto in protocols:
+ for s in b'', b'xyz', b'xyz'*100:
+ b = bytearray(s)
+ p = self.dumps((b, b), proto)
+ b1, b2 = self.loads(p)
+ self.assertIs(b1, b2)
+
def test_ints(self):
for proto in protocols:
n = sys.maxsize
diff --git a/Misc/NEWS.d/next/Library/2021-04-23-20-57-20.bpo-43907.3RJEjv.rst b/Misc/NEWS.d/next/Library/2021-04-23-20-57-20.bpo-43907.3RJEjv.rst
new file mode 100644
index 0000000..7da3a1c
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2021-04-23-20-57-20.bpo-43907.3RJEjv.rst
@@ -0,0 +1,4 @@
+Fix a bug in the pure-Python pickle implementation when using protocol 5,
+where bytearray instances that occur several time in the pickled object
+graph would incorrectly unpickle into repeated copies of the bytearray
+object.