Fix bug in upload/download of hsdesc with microdescs

Previously we were using router_get_by_id(foo) to test "do we have a
descriptor that will let us make an anonymous circuit to foo".  But
that isn't right for microdescs: we should have been using node_t.

Fixes bug 3601; bugfix on 0.2.3.1-alpha.

changes/bug3601

@@ -0,0 +1,4 @@
+  o Major bugfixes:
+    - Using microdescriptors no longer prevents Tor from uploading and
+      downloading hidden service descriptors. Fixes bug 3601; bugfix
+      on 0.2.3.1-alpha.

src/or/rendclient.c

@@ -510,10 +510,11 @@ directory_get_from_hs_dir(const char *desc_id, const rend_data_t *rend_query)
   directory_clean_last_hid_serv_requests(now);
 
   SMARTLIST_FOREACH(responsible_dirs, routerstatus_t *, dir, {
-    if (lookup_last_hid_serv_request(dir, desc_id_base32, 0, 0) +
-            REND_HID_SERV_DIR_REQUERY_PERIOD >= now ||
-        !router_get_by_id_digest(dir->identity_digest))
-      SMARTLIST_DEL_CURRENT(responsible_dirs, dir);
+      time_t last = lookup_last_hid_serv_request(dir, desc_id_base32, 0, 0);
+      const node_t *node = node_get_by_id(dir->identity_digest);
+      if (last + REND_HID_SERV_DIR_REQUERY_PERIOD >= now ||
+          !node || !node_has_descriptor(node))
+        SMARTLIST_DEL_CURRENT(responsible_dirs, dir);
   });
 
   hs_dir = smartlist_choose(responsible_dirs);

src/or/rendservice.c

@@ -1632,12 +1632,14 @@ directory_post_to_hs_dir(rend_service_descriptor_t *renddesc,
     for (j = 0; j < smartlist_len(responsible_dirs); j++) {
       char desc_id_base32[REND_DESC_ID_V2_LEN_BASE32 + 1];
       char *hs_dir_ip;
+      const node_t *node;
       hs_dir = smartlist_get(responsible_dirs, j);
       if (smartlist_digest_isin(renddesc->successful_uploads,
                                 hs_dir->identity_digest))
         /* Don't upload descriptor if we succeeded in doing so last time. */
         continue;
-      if (!router_get_by_id_digest(hs_dir->identity_digest)) {
+      node = node_get_by_id(hs_dir->identity_digest);
+      if (!node || !node_has_descriptor(node)) {
         log_info(LD_REND, "Not sending publish request for v2 descriptor to "
                           "hidden service directory %s; we don't have its "
                           "router descriptor. Queuing for later upload.",