tarfile.TarFile.next() adds an unnecessary traceback frame when reraising exceptions

description:

https://gist.github.com/devdanzin/f8af359770ff200eac8474de5644be82

tarfile.TarFile.next() currently reraises non-zlib exceptions with raise e
inside its generic exception handler:

except Exception as e:
    try:
        import zlib
        if isinstance(e, zlib.error):
            raise ReadError(f'zlib error: {e}') from None
        else:
            raise e
    except ImportError:
        raise e

Using raise e adds an extra traceback frame at the re-raise site. A bare
raise would keep the traceback cleaner while preserving the original exception
and its traceback.

CPython versions tested on:

3.14, CPython main branch

Operating systems tested on:

Windows

Linked PRs

• gh-149761
• gh-157257

Search the tarfile module for TarFile.next() and inspect the generic exception handler shown in the issue. Confirm the traceback difference described in the linked gist, then run the tarfile tests after the exception-handling change to verify that non-zlib exceptions retain their original traceback and zlib errors remain unchanged.