apache_1.3.22/src/modules/standard/mod_negotiation.c

2529     alg_result = best_match(neg, bestp);
2530
2531     /* alg_result is one of
2532      *   alg_choice: a best variant is chosen
2533      *   alg_list: no best variant is chosen
2534      */
2535
2536     if (alg_result == alg_list) {
2537         /* send a list response or NOT_ACCEPTABLE error response  */

2560         if (!*bestp) {
2561             ap_log_rerror(APLOG_MARK, APLOG_NOERRNO|APLOG_ERR, r,
2562                           "no acceptable variant: %s", r->filename);
2563             return NOT_ACCEPTABLE;
2564         }

best_match で何も返って来ていないことが良くないけれど、 そもそも、ここに来ること自体が変。
handle_map_file(request_rec *r) ... res = do_negotiation(r, neg, &best, 0);
handle_multi(request_rec *r) ... res = do_negotiation(r, neg, &best,
同じく

2800 static const handler_rec negotiation_handlers[] =
2801 {
2802     {MAP_FILE_MAGIC_TYPE, handle_map_file},
2803     {"type-map", handle_map_file},

2807 module MODULE_VAR_EXPORT negotiation_module =
2808 {
2809     STANDARD_MODULE_STUFF,
2810     NULL,                       /* initializer */
.....
2821     handle_multi,               /* type_checker */
2822     fix_encoding,               /* fixups */