Re: mdocml: Don't crash if the date can't be extracted.

[Ingo Schwarze <schwarze@usta.de>]

Hi Joerg,

i don't understand this.

If there is no title, check_root (in man_validate.c) provides defaults.

If there is a title, but no date, post_TH (in man_validate.c)
sets the date to the empty string, and the same holds for the
section.

Can you provide examples triggering these NULL pointer accesses?

Have a look at

  http://www.openbsd.org/cgi-bin/cvsweb/src/regress/usr.bin/mandoc/man/TH/

These tests all work for me without your patch.

Thanks,
  Ingo

joerg@mdocml.bsd.lv wrote on Fri, Nov 18, 2011 at 12:04:06PM -0500:

> Log Message:
> -----------
> Don't crash if the date can't be extracted. Don't depend on snprintf
> handling NULL strings.
> 
> Modified Files:
> --------------
>     mdocml:
>         man_term.c
> 
> Revision Data
> -------------
> Index: man_term.c
> ===================================================================
> RCS file: /home/joerg/cvsroot/mdocml/man_term.c,v
> retrieving revision 1.123
> retrieving revision 1.124
> diff -Lman_term.c -Lman_term.c -u -p -r1.123 -r1.124
> --- man_term.c
> +++ man_term.c
> @@ -969,8 +969,9 @@ print_man_foot(struct termp *p, const vo
>  	term_vspace(p);
>  	term_vspace(p);
>  	term_vspace(p);
> -	snprintf(title, BUFSIZ, "%s(%s)", meta->title, meta->msec);
> -	datelen = term_strlen(p, meta->date);
> +	snprintf(title, BUFSIZ, "%s(%s)", meta->title ? meta->title : "",
> +	    meta->msec ? meta->msec : "");
> +	datelen = term_strlen(p, meta->date ? meta->date : "");
>  
>  	p->flags |= TERMP_NOSPACE | TERMP_NOBREAK;
>  	p->offset = 0;
> @@ -986,7 +987,7 @@ print_man_foot(struct termp *p, const vo
>  	if (p->offset + datelen >= p->rmargin)
>  		p->rmargin = p->offset + datelen;
>  
> -	term_word(p, meta->date);
> +	term_word(p, meta->date ? meta->date : "");
>  	term_flushln(p);
>  
>  	p->flags &= ~TERMP_NOBREAK;
> @@ -1023,7 +1024,8 @@ print_man_head(struct termp *p, const vo
>  		strlcpy(buf, m->vol, BUFSIZ);
>  	buflen = term_strlen(p, buf);
>  
> -	snprintf(title, BUFSIZ, "%s(%s)", m->title, m->msec);
> +	snprintf(title, BUFSIZ, "%s(%s)", m->title ? m->title : "",
> +	    m->msec ? m->msec : "");
>  	titlen = term_strlen(p, title);
>  
>  	p->flags |= TERMP_NOBREAK | TERMP_NOSPACE;
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