Re: [PATCH 5/6] More accurately detect header lines in read_one_header_line

From: Junio C Hamano <junkio@cox.net>
Date: May 26, 2006, 07:29 UTC
Message-ID: <7vy7wpnt0t.fsf@assigned-by-dhcp.cox.net>
In-Reply-To: <m1mzd8iklr.fsf_-_@ebiederm.dsl.xmission.com>

ebiederm@xmission.com (Eric W. Biederman) writes:

> Only count lines of the form '^.*: ' and '^From ' as email
> header lines.

I am having trouble with this patch.

Show 22 quoted lines

> diff --git a/mailinfo.c b/mailinfo.c
> index 99989c2..c642ff4 100644
> --- a/mailinfo.c
> +++ b/mailinfo.c
> @@ -385,20 +385,29 @@ static int read_one_header_line(char *li
>  {
>  	int ofs = 0;
>  	while (ofs < sz) {
> +		const char *colon;
>  		int peek, len;
>  		if (fgets(line + ofs, sz - ofs, in) == NULL)
> +			break;
>  		len = eatspace(line + ofs);
>  		if (len == 0)
> +			break;
> +		colon = strchr(line, ':');
> +		if (!colon || !isspace(colon[1])) {
> +			/* Readd the newline */
> +			line[ofs + len] = '\n';
> +			line[ofs + len + 1] = '\0';
> +			break;
>  		}

Because eatspace() eats the trailing space, although your commit message say lines matching "^.*: " are headers, this does not match the criteria:

        X-Spam-Checker-Version: SpamAssassin 3.1.1 (2006-03-10) on 
                gitster.siamese.dyndns.org
->      X-Spam-Level: 
        X-Spam-Status: No, score=-2.6 required=5.0 tests=BAYES_00
        	autolearn=ham version=3.1.1

Notice that the field body for this unstructured header X-Spam-Level (an optional field) consists of a single whitespace. It will be gone because of eatspace() when your check sees the line, so the header parsing stops prematurely.

Was there a particular reason you needed this change? That is, did you have to parse mail-looking input that does not have a blank line between runs of headers and the body of the message?

If so, I'd at least like to remove the || !isspace(colon[1]) from the test. After all, I do not think RFC2822 requires a whitespace after the colon there.