Stowage/cpython
2
0
Fork 0
mirror of https://github.com/python/cpython.git synced 2025-12-08 06:10:17 +00:00
Code Issues Projects Releases Packages Wiki Activity

[3.14] gh-141311: Avoid assertion in BytesIO.readinto() (GH-141333) (GH-141457)

Browse source 
Fix error in assertion which causes failure if pos is equal to PY_SSIZE_T_MAX.
Fix undefined behavior in read() and readinto() if pos is larger that the size
of the underlying buffer.
(cherry picked from commit 7d54374f9c)

Co-authored-by: Cody Maloney <cmaloney@users.noreply.github.com>
This commit is contained in:
Miss Islington (bot) 2025-11-12 11:23:26 +01:00 • committed by GitHub
parent b883ad17cd
commit 75b5157e84
No known key found for this signature in database
GPG key ID: B5690EEEBB952194
3 changed files with 29 additions and 3 deletions
Download patch file Download diff file Expand all files Collapse all files

14
Lib/test/test_memoryio.py
View file

@ -54,6 +54,12 @@ def testSeek(self):
self.assertEqual(buf[3:], bytesIo.read())
self.assertRaises(TypeError, bytesIo.seek, 0.0)
self.assertEqual(sys.maxsize, bytesIo.seek(sys.maxsize))
self.assertEqual(self.EOF, bytesIo.read(4))
self.assertEqual(sys.maxsize - 2, bytesIo.seek(sys.maxsize - 2))
self.assertEqual(self.EOF, bytesIo.read(4))
def testTell(self):
buf = self.buftype("1234567890")
bytesIo = self.ioclass(buf)
@ -552,6 +558,14 @@ def test_relative_seek(self):
memio.seek(1, 1)
self.assertEqual(memio.read(), buf[1:])
def test_issue141311(self):
memio = self.ioclass()
# Seek allows PY_SSIZE_T_MAX, read should handle that.
# Past end of buffer read should always return 0 (EOF).
self.assertEqual(sys.maxsize, memio.seek(sys.maxsize))
buf = bytearray(2)
self.assertEqual(0, memio.readinto(buf))
def test_unicode(self):
memio = self.ioclass()