Changes file and comment for 25928.

changes/ticket25928

@@ -0,0 +1,4 @@
+  o Minor features (directory):
+    - Improved support for networks with only a single authority or a
+      single fallback directory. Patch from Gabriel Somlo. Closes
+      ticket 25928.

src/feature/nodelist/routerlist.c

@@ -1806,8 +1806,11 @@ router_pick_dirserver_generic(smartlist_t *sourcelist,
   const routerstatus_t *choice;
   int busy = 0;
 
-  if (smartlist_len(sourcelist) == 1)
+  if (smartlist_len(sourcelist) == 1) {
+    /* If there's only one choice, then we should disable the logic that
+     * would otherwise prevent us from choosing ourself. */
     flags |= PDS_ALLOW_SELF;
+  }
 
   choice = router_pick_trusteddirserver_impl(sourcelist, type, flags, &busy);
   if (choice || !(flags & PDS_RETRY_IF_NO_SERVERS))