Re: [PATCH v5 03/13] bisect--helper: introduce new `write_in_file()` function

From: Junio C Hamano <gitster@pobox.com>
Date: Jul 17, 2020, 16:33 UTC
Message-ID: <xmqqzh7ydrt6.fsf@gitster.c.googlers.com>
In-Reply-To: <20200717105406.82226-4-mirucam@gmail.com>

Miriam Rubio <mirucam@gmail.com> writes:

Show 8 quoted lines

> +	fp = fopen(path, mode);
> +	if (!fp)
> +		return error_errno(_("cannot open file '%s' in mode '%s'"), path, mode);
> +	res = vfprintf(fp, format, args);
> +
> +	if (res < 0) {
> +		fclose(fp);
> +		return error_errno(_("could not write to file '%s'"), path);

If the fclose(fp) failed, the errno from that failure (i.e. why fp cannot be closed) would be reported by the error_errno(), which may not be ideal. Either use just error() (which may be suboptimal), follow an often-used pattern to use save_errno (grep for the symbol to learn from the existing code) and keep using error_errno(), or check errors from fclose() too (which may be overkill).

	if (res < 0) {
		int saved_errno = errno;
#if OVERKILL
		if (fclose(fp))
                	error_errno(_("..."));
#else
		fclose(fp);
#endif
		errno = saved_errno;
		return error_errno(_("..."), ...);
	}