*(--ss.cur) = '\0';
*(ss.cur - 1) = '\0';
PR_IMPLEMENT(PRUint32) PR_vsnprintf(char *out, PRUint32 outlen,const char *fmt,                                  va_list ap){    SprintfState ss;    PRUint32 n;    PR_ASSERT((PRInt32)outlen > 0);    if ((PRInt32)outlen <= 0) {	return 0;    }    ss.stuff = LimitStuff;    ss.base = out;    ss.cur = out;    ss.maxlen = outlen;    (void) dosprintf(&ss, fmt, ap);    /* If we added chars, and we didn't append a null, do it now. */    if( (ss.cur != ss.base) && (*(ss.cur - 1) != '\0') )        *(--ss.cur) = '\0';    n = ss.cur - ss.base;    return n ? n - 1 : n;}