cvs-printf-n.patch

   1 --- cvs-1.12.13/lib/vasnprintf.c        2005-05-23 19:44:33.000000000 +0200
   2 +++ cvs-1.12.13/lib/vasnprintf.c        2009-02-10 20:38:47.947197650 +0100
   3 @@ -558,9 +558,21 @@
   4                   }
   5                 *p = dp->conversion;
   6  #if USE_SNPRINTF
   7 -               p[1] = '%';
   8 -               p[2] = 'n';
   9 -               p[3] = '\0';
  10 +# if !(__GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 3))
  11 +               p[1] = '%';
  12 +               p[2] = 'n';
  13 +               p[3] = '\0';
  14 +# else
  15 +               /* On glibc2 systems from glibc >= 2.3 - probably also older
  16 +                  ones - we know that snprintf's returns value conforms to
  17 +                  ISO C 99: the gl_SNPRINTF_DIRECTIVE_N test passes.
  18 +                  Therefore we can avoid using %n in this situation.
  19 +                  On glibc2 systems from 2004-10-18 or newer, the use of %n
  20 +                  in format strings in writable memory may crash the program
  21 +                  (if compiled with _FORTIFY_SOURCE=2), so we should avoid it
  22 +                  in this situation.  */
  23 +               p[1] = '\0';
  24 +# endif
  25  #else
  26                 p[1] = '\0';
  27  #endif