https://github.com/python/cpython/commit/df59b64589e32a2b2b43703cce62aad2ea0cfe1b commit: df59b64589e32a2b2b43703cce62aad2ea0cfe1b branch: 3.12 author: Miss Islington (bot) <[email protected]> committer: brettcannon <[email protected]> date: 2024-11-13T14:49:47-08:00 summary:
[3.12] GH-126606: don't write incomplete pyc files (GH-126627) (GH-126810) GH-126606: don't write incomplete pyc files (GH-126627) (cherry picked from commit c695e37a3f95c225ee08d1e882d23fa200b5ec34) Co-authored-by: CF Bolz-Tereick <[email protected]> Co-authored-by: Kirill Podoprigora <[email protected]> Co-authored-by: Brett Cannon <[email protected]> files: A Misc/NEWS.d/next/Core_and_Builtins/2024-11-09-16-10-22.gh-issue-126066.9zs4m4.rst M Lib/importlib/_bootstrap_external.py M Lib/test/test_importlib/test_util.py diff --git a/Lib/importlib/_bootstrap_external.py b/Lib/importlib/_bootstrap_external.py index 61dafc0f4cb953..9b8a8dfc5aae28 100644 --- a/Lib/importlib/_bootstrap_external.py +++ b/Lib/importlib/_bootstrap_external.py @@ -204,7 +204,11 @@ def _write_atomic(path, data, mode=0o666): # We first write data to a temporary file, and then use os.replace() to # perform an atomic rename. with _io.FileIO(fd, 'wb') as file: - file.write(data) + bytes_written = file.write(data) + if bytes_written != len(data): + # Raise an OSError so the 'except' below cleans up the partially + # written file. + raise OSError("os.write() didn't write the full pyc file") _os.replace(path_tmp, path) except OSError: try: diff --git a/Lib/test/test_importlib/test_util.py b/Lib/test/test_importlib/test_util.py index e018af2e16beab..553e2087421835 100644 --- a/Lib/test/test_importlib/test_util.py +++ b/Lib/test/test_importlib/test_util.py @@ -6,12 +6,14 @@ importlib_util = util.import_importlib('importlib.util') import importlib.util +from importlib import _bootstrap_external import os import pathlib import re import string import sys from test import support +from test.support import os_helper import textwrap import types import unittest @@ -758,5 +760,35 @@ def test_complete_multi_phase_init_module(self): self.run_with_own_gil(script) +class MiscTests(unittest.TestCase): + def test_atomic_write_should_notice_incomplete_writes(self): + import _pyio + + oldwrite = os.write + seen_write = False + + truncate_at_length = 100 + + # Emulate an os.write that only writes partial data. + def write(fd, data): + nonlocal seen_write + seen_write = True + return oldwrite(fd, data[:truncate_at_length]) + + # Need to patch _io to be _pyio, so that io.FileIO is affected by the + # os.write patch. + with (support.swap_attr(_bootstrap_external, '_io', _pyio), + support.swap_attr(os, 'write', write)): + with self.assertRaises(OSError): + # Make sure we write something longer than the point where we + # truncate. + content = b'x' * (truncate_at_length * 2) + _bootstrap_external._write_atomic(os_helper.TESTFN, content) + assert seen_write + + with self.assertRaises(OSError): + os.stat(support.os_helper.TESTFN) # Check that the file did not get written. + + if __name__ == '__main__': unittest.main() diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2024-11-09-16-10-22.gh-issue-126066.9zs4m4.rst b/Misc/NEWS.d/next/Core_and_Builtins/2024-11-09-16-10-22.gh-issue-126066.9zs4m4.rst new file mode 100644 index 00000000000000..9c0072304ded63 --- /dev/null +++ b/Misc/NEWS.d/next/Core_and_Builtins/2024-11-09-16-10-22.gh-issue-126066.9zs4m4.rst @@ -0,0 +1,3 @@ +Fix :mod:`importlib` to not write an incomplete .pyc files when a ulimit or some +other operating system mechanism is preventing the write to go through +fully. _______________________________________________ Python-checkins mailing list -- [email protected] To unsubscribe send an email to [email protected] https://mail.python.org/mailman3/lists/python-checkins.python.org/ Member address: [email protected]
