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Date: Sat, 14 Jun 1997 09:07:46 -0400 (EDT)
From: Tim Vanderhoek <tim@X2296>
Reply-To: ac199@hwcn.org
To: Bruce Evans <bde@zeta.org.au>
cc: ac199@hwcn.org, freebsd-bugs@hub.freebsd.org,
        freebsd-gnats-submit@freebsd.org
Subject: Re: bin/3451: vasprintf() doesn't work.
In-Reply-To: <199706140156.LAA12946@godzilla.zeta.org.au>
Message-ID: <Pine.BSF.3.95q.970614085707.169A-100000@X2296>
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On Sat, 14 Jun 1997, Bruce Evans wrote:

> >   	*str = realloc(h.base, (size_t)(h.size - h.left + 1));
> >   	if (*str == NULL)	/* failed to realloc it to actual size */
> > ! 		return (-1);
> > ! 	(*str)[h.size - h.left] = '\0';
> >   	return (ret);
> >   }
> 
> One more problem: realloc() can fail, resulting in a leaking the memory
> pointed to by h.base.

Which, of course, points us to yet another error in the original
vasprintf.c...  :)  The test to see if str is NULL is
*str == NULL....

Final patch frees h.base (as is done everywhere else) and fixes 
that... :)


*** old.vasprintf.c	Tue Apr 29 21:32:00 1997
--- vasprintf.c	Sat Jun 14 08:56:41 1997
***************
*** 111,119 ****
  	if (h.base == NULL)	/* failed to realloc in writehook */
  		return (-1);
  
- 	h.base[h.size - h.left] = '\0';
  	*str = realloc(h.base, (size_t)(h.size - h.left + 1));
! 	if (*str == NULL)	/* failed to realloc it to actual size */
! 		*str = h.base;	/* return oversize buffer */
  	return (ret);
  }
--- 111,121 ----
  	if (h.base == NULL)	/* failed to realloc in writehook */
  		return (-1);
  
  	*str = realloc(h.base, (size_t)(h.size - h.left + 1));
! 	if (str == NULL) {	/* failed to realloc it to actual size */
! 		free(h.base);
! 		return (-1);
! 	}
! 	(*str)[h.size - h.left] = '\0';
  	return (ret);
  }


--
tIM...HOEk
optimization: The theory that making your code incomprehensible by using
              only one-letter variable names will make it run faster.