[tor-bugs] #24161 [Core Tor/Tor]: Recalculating voting schedule should be called first when setting a new consensus

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#24161: Recalculating voting schedule should be called first when setting a new
consensus
------------------------------+--------------------------------
     Reporter:  dgoulet       |      Owner:  dgoulet
         Type:  defect        |     Status:  assigned
     Priority:  Medium        |  Milestone:  Tor: 0.3.2.x-final
    Component:  Core Tor/Tor  |    Version:
     Severity:  Normal        |   Keywords:  tor-sr, tor-relay
Actual Points:                |  Parent ID:
       Points:                |   Reviewer:
      Sponsor:                |
------------------------------+--------------------------------
 In `networkstatus_set_current_consensus()`, at some point the `if
 (is_usable_flavor)` does a series of action on the newly set consensus.

 One of those is `nodelist_set_consensus()` which among many things will
 compute the HSv3 HSDir index for every `node_t` in this new consensus.
 That step requires the voting schedule object to be defined too compute
 time periods that the HS subsystem needs requiring the voting schedule
 timings.

 So, the very first thing we should do when we get a new usable consensus
 is set its voting schedule timings. That is call
 `dirvote_recalculate_timing(options, now);` which is currently after the
 nodelist set.

 This has been observed by this Bug when tor starts with the latest change
 in #23623:

 {{{
 Nov 07 15:39:09.364 [notice] Bootstrapped 0%: Starting
 Nov 07 15:39:09.978 [warn] tor_timegm(): Bug: Out-of-range argument to
 tor_timegm (on Tor 0.3.3.0-alpha-dev c6c4a421fd7d8a0d)
 Nov 07 15:39:09.978 [warn] dirvote_get_start_of_next_interval(): Bug: Ran
 into an invalid time when trying to find midnight. (on Tor 0.3.3.0-alpha-
 dev c6c4a421fd7d8a0d)
 ...
 }}}

 The other thing I wondered is if we should add a safe guard to the public
 function `dirvote_get_next_valid_after_time()` to calculate the timings in
 case the voting schedule is zeroed because in this case, this is where the
 issue comes from, that function returns 0.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/24161>
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