Merge remote-tracking branch 'asn/bug21052'

diff --cc src/or/entrynodes.c
index e341739379d2bb827cdaa5311a4c23a06133ce85,e26f32d56e9917b747cb2947295732e2081f6d39..b7c05f1930fd3fb6729168aac3d60f2bd183cbaf
--- 1/src/or/entrynodes.c
--- 2/src/or/entrynodes.c
+++ b/src/or/entrynodes.c
@@@ -1851,10 -1944,11 +1897,12 @@@ select_entry_guard_for_circuit(guard_se
                                                     rst,
                                                     SAMPLE_EXCLUDE_CONFIRMED |
                                                     SAMPLE_EXCLUDE_PRIMARY |
 -                                                   SAMPLE_EXCLUDE_PENDING);
 +                                                   SAMPLE_EXCLUDE_PENDING |
 +                                                   flags);
      if (guard == NULL) {
-       log_info(LD_GUARD, "Absolutely no sampled guards were available.");
+       log_info(LD_GUARD, "Absolutely no sampled guards were available. "
+                "Marking all guards for retry and starting from top again.");
+       mark_all_guards_maybe_reachable(gs);
        return NULL;
      }
      guard->is_pending = 1;