From: Andreas Schwab <schwab@linux-m68k.org>
Date: Tue, 05 Apr 2016 17:41:58 GMT
Subject: Re: Timestamp of zero in reflog considered invalid
Message-ID: <87r3ek3qc9.fsf@linux-m68k.org>
In-Reply-To: <xmqqbn5o2gv1.fsf@gitster.mtv.corp.google.com>

Junio C Hamano <gitster@pobox.com> writes:

> Checking the value against ULONG_MAX and errno==ERANGE would be an
> improvement.  It may be debatable if we should silently ignore an
> entry with an invalid timestamp, but that is a separate issue.
>
>  refs.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/refs.c b/refs.c
> index 4e15f60..ff24184 100644
> --- a/refs.c
> +++ b/refs.c
> @@ -3701,7 +3701,8 @@ static int show_one_reflog_ent(struct strbuf *sb, each_reflog_ent_fn fn, void *c
>  	    get_sha1_hex(sb->buf + 41, nsha1) || sb->buf[81] != ' ' ||
>  	    !(email_end = strchr(sb->buf + 82, '>')) ||
>  	    email_end[1] != ' ' ||
> -	    !(timestamp = strtoul(email_end + 2, &message, 10)) ||
> +	    ((timestamp = strtoul(email_end + 2, &message, 10)) == ULONG_MAX &&
> +	     errno == ERANGE) ||

You need to set errno = 0 before calling strtoul, to distinguish the
valid return of ULONG_MAX (which would keep errno intact) and a real
overflow.

Andreas.

-- 
Andreas Schwab, schwab@linux-m68k.org
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