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

*** 233,243 ****
  
          if (fwd != (char *) NULL) {
              if (cl != (cr = wcsrchr(n, (wchar_t)'!'))) {
                  /*  more than one ! */
                  wcsncpy(tmpbuf, cl+1, cr-cl-1);
!                 tmpbuf[cr-cl-1] = NULL;
                  (void) wcstombs(fwd, tmpbuf, MAXFULLNAME);
              }
          } else {
              cr = cl;
          }
--- 233,243 ----
  
          if (fwd != (char *) NULL) {
              if (cl != (cr = wcsrchr(n, (wchar_t)'!'))) {
                  /*  more than one ! */
                  wcsncpy(tmpbuf, cl+1, cr-cl-1);
!                 tmpbuf[cr-cl-1] = L'\0';
                  (void) wcstombs(fwd, tmpbuf, MAXFULLNAME);
              }
          } else {
              cr = cl;
          }