const char *zFrom = P("from");
  const char *zTo = P("to");
  DiffConfig DCfg;
  cgi_check_for_malice();
  login_check_credentials();
  if( !g.perm.Read ){ login_needed(g.anon.Read); return; }
  if( zFrom==0 || zTo==0 ) fossil_redirect_home();
  if( robot_squelch(800) ) return;

  fossil_nice_default();
  cgi_set_content_type("text/plain");
  diff_config_init(&DCfg, DIFF_VERBOSE);
  diff_two_versions(zFrom, zTo, &DCfg, 0);
}