[PATCH] Adjust pointers to triplets in netgroup query data (BZ #16474)

[Ondřej Bílka]

On Fri, Jan 24, 2014 at 04:18:43PM +0100, Andreas Schwab wrote:
> Siddhesh Poyarekar <siddhesh@redhat.com> writes:
> 
> > @@ -241,7 +241,17 @@ addgetnetgrentX (struct database_dyn *db, int fd, request_header *req,
> >  				if (buflen - req->key_len - bufused < needed)
> >  				  {
> >  				    buflen += MAX (buflen, 2 * needed);
> > -				    buffer = xrealloc (buffer, buflen);
> > +				    char *newbuf = xrealloc (buffer, buflen);
> > +				    /* Adjust the pointers in the new
> > +				       buffer.  */
> > +				    nhost = (nhost ? newbuf + (nhost - buffer)
> 
> This is undefined.  If realloc was sucessful then buffer is no longer
> valid.  You need to compute nhost - buffer before doing the realloc.
> 
As these are not referenced it leads to equivalent code. Only problem with that code
would be static analyzer flagging this as false positive.