GzipFile leaves GzipFile.myfileobject open in constructor if exception is raised

[graingert]

Bug report

Bug description:

consider the following program, it should raise an ExceptionGroup(..., [ValueError(), ValueError(), ...] but actually it raises OSError: [Errno 24] Too many open files: '/tmp/tmpk8gaprry'

import gzip
import tempfile
import pathlib
import os

def main():
    with tempfile.TemporaryDirectory() as tmp_dir:
        tmp_path = pathlib.Path(tmp_dir)
        zip_path = tmp_path / "some_file.zip"

        exceptions = []
        for i in range(2000):
            try:
                gzip.GzipFile(filename=os.fsdecode(zip_path), mode="w", compresslevel=99)
            except ValueError as e:
                exceptions.append(e)
        if exceptions:
            raise ExceptionGroup("multiple errors creating GzipFiles", exceptions)

main()

CPython versions tested on:

CPython main branch, 3.14, 3.13, 3.12, 3.11

Operating systems tested on:

Linux

Linked PRs

• gh-131492: gh-131461: handle exceptions in GzipFile constructor while owning resources #131462
• [3.13] gh-131492, gh-131461: handle exceptions in GzipFile constructor while owning resources (GH-131462) #131518
• [3.12] gh-131492, gh-131461: handle exceptions in GzipFile constructor while owning resources (GH-131462) #131519

[vstinner]

Fixed by the change ce79274.

[vstinner]

consider the following program, it should raise an ExceptionGroup(..., [ValueError(), ValueError(), ...] but actually it raises OSError: [Errno 24] Too many open files: '/tmp/tmpk8gaprry'

I confirm that it now raises the ExceptionGroup, rather than failing with "Too many open files". It works as expected.