Issue #23094: Fixed readline with frames in Python implementation of pickle.

Lib/pickle.py

@@ -242,7 +242,7 @@ class _Unframer:
             if not data:
                 self.current_frame = None
                 return self.file_readline()
-            if data[-1] != b'\n':
+            if data[-1] != b'\n'[0]:
                 raise UnpicklingError(
                     "pickle exhausted before end of frame")
             return data

Lib/test/pickletester.py

@@ -1538,6 +1538,14 @@ class AbstractPickleTests(unittest.TestCase):
                             count_opcode(pickle.FRAME, pickled))
             self.assertEqual(obj, self.loads(some_frames_pickle))
 
+    def test_frame_readline(self):
+        pickled = b'\x80\x04\x95\x05\x00\x00\x00\x00\x00\x00\x00I42\n.'
+        #    0: \x80 PROTO      4
+        #    2: \x95 FRAME      5
+        #   11: I    INT        42
+        #   15: .    STOP
+        self.assertEqual(self.loads(pickled), 42)
+
     def test_nested_names(self):
         global Nested
         class Nested:

Misc/NEWS

@@ -50,6 +50,8 @@ Core and Builtins
 Library
 -------
 
+- Issue #23094: Fixed readline with frames in Python implementation of pickle.
+
 - Issue #23268: Fixed bugs in the comparison of ipaddress classes.
 
 - Issue #21408: Removed incorrect implementations of __ne__() which didn't