From cb07bc3f7ab2c8511e22f45e4304df77c574ca8e Mon Sep 17 00:00:00 2001 From: Victor Stinner Date: Fri, 14 Aug 2026 14:33:01 +0200 Subject: [PATCH] gh-155742: Test PyBytesWriter_FinishWithSize() with negative size (GH-155783) Add test_finish_with_size() to test_capi.test_bytes. (cherry picked from commit b8e23da18a5ddd86f85f7654e3b4565c82623456) Co-authored-by: Victor Stinner --- Lib/test/test_capi/test_bytes.py | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/Lib/test/test_capi/test_bytes.py b/Lib/test/test_capi/test_bytes.py index c591e986bbce35..d20e5016f969c2 100644 --- a/Lib/test/test_capi/test_bytes.py +++ b/Lib/test/test_capi/test_bytes.py @@ -315,10 +315,16 @@ def test_create(self): self.assertEqual(writer.get_size(), 3) self.assertEqual(writer.finish(), self.result_type(b'abc')) + def test_finish_with_size(self): + # Test PyBytesWriter_FinishWithSize() writer = self.create_writer(10, b'abc') self.assertEqual(writer.get_size(), 10) self.assertEqual(writer.finish_with_size(3), self.result_type(b'abc')) + writer = self.create_writer(3, b'abc') + with self.assertRaises(SystemError): + writer.finish_with_size(-3) + def test_write_bytes(self): # Test PyBytesWriter_WriteBytes() writer = self.create_writer()