}
NORETURN void cgi_redirectf(const char *zFormat, ...){
  va_list ap;
  va_start(ap, zFormat);
  cgi_redirect(vmprintf(zFormat, ap));
  va_end(ap);
}

/*
** Add a "Content-disposition: attachment; filename=%s" header to the reply.
*/
void cgi_content_disposition_filename(const char *zFilename){
  char *z;
  int i, n;

           /*  0123456789 123456789 123456789 123456789 123456*/
  z = mprintf("Content-Disposition: attachment; filename=\"%s\";\r\n",
                    file_tail(zFilename));
  n = (int)strlen(z);
  for(i=43; i<n-4; i++){
    char c = z[i];
    if( fossil_isalnum(c) ) continue;
    if( c=='.' || c=='-' || c=='/' ) continue;
    z[i] = '_';
  }
  cgi_append_header(z);
  fossil_free(z);
}

/*
** Return the URL for the caller.  This is obtained from either the
** referer CGI parameter, if it exists, or the HTTP_REFERER HTTP parameter.
** If neither exist, return zDefault.
*/
const char *cgi_referer(const char *zDefault){