5218 posix definition of NULL
correct unistd.h and iso/stddef_iso.h
update gate source affected

*** 300,322 ****
                  if (t_getstate(fd) != T_DATAXFER)
                          return (FAIL);
          }
  
          if (info.tsdu <= 0 || nbytes <= info.tsdu)
!                 return (t_snd(fd, buf, nbytes, NULL));
  
          /* if get here, then there is a limit on transmit size  */
          /* (info.tsdu > 0) and buf exceeds it                   */
          i = ret = 0;
          while (nbytes >= info.tsdu) {
!                 if ((ret = t_snd(fd,  &buf[i], info.tsdu, NULL)) != info.tsdu)
                          return ((ret >= 0 ? (i + ret) : ret));
                  i += info.tsdu;
                  nbytes -= info.tsdu;
          }
          if (nbytes != 0) {
!                 if ((ret = t_snd(fd,  &buf[i], nbytes, NULL)) != nbytes)
                          return ((ssize_t)(ret >= 0 ? (i + ret) : ret));
                  i += nbytes;
          }
          return ((ssize_t)i);
  }
--- 300,322 ----
                  if (t_getstate(fd) != T_DATAXFER)
                          return (FAIL);
          }
  
          if (info.tsdu <= 0 || nbytes <= info.tsdu)
!                 return (t_snd(fd, buf, nbytes, 0));
  
          /* if get here, then there is a limit on transmit size  */
          /* (info.tsdu > 0) and buf exceeds it                   */
          i = ret = 0;
          while (nbytes >= info.tsdu) {
!                 if ((ret = t_snd(fd,  &buf[i], info.tsdu, 0)) != info.tsdu)
                          return ((ret >= 0 ? (i + ret) : ret));
                  i += info.tsdu;
                  nbytes -= info.tsdu;
          }
          if (nbytes != 0) {
!                 if ((ret = t_snd(fd,  &buf[i], nbytes, 0)) != nbytes)
                          return ((ssize_t)(ret >= 0 ? (i + ret) : ret));
                  i += nbytes;
          }
          return ((ssize_t)i);
  }