[tor-bugs] #20533 [Core Tor/Tor]: Each download request should only increment the failure count once

[Tor Bug Tracker & Wiki]

#20533: Each download request should only increment the failure count once
--------------------------+------------------------------------
 Reporter:  teor          |          Owner:
     Type:  defect        |         Status:  new
 Priority:  Medium        |      Milestone:  Tor: 0.2.9.x-final
Component:  Core Tor/Tor  |        Version:
 Severity:  Normal        |     Resolution:
 Keywords:  regression    |  Actual Points:
Parent ID:  #20499        |         Points:  1
 Reviewer:                |        Sponsor:
--------------------------+------------------------------------

Comment (by teor):

 Replying to [comment:3 nickm]:
 > I am trying to understand what you're saying in the description above.
 What causes the second call to download_status_increment_failure() ?  Does
 this have something to do with parallel requests?

 Not really.

 If check_consensus_waiting_for_certs is called when we've been waiting
 longer than DELAY_WHILE_FETCHING_CERTS, it calls
 `download_status_failed(dls, 0);`.

 This is the source of the second failure, and in most cases it should be
 counted as a failure - we successfully downloaded a consensus, but could
 not download enough certificates to validate it.

 That said, we should probably fail `check_consensus_waiting_for_certs` if
 the consensus we're waiting for has expired, too. But this could wait for
 0.3.0.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/20533#comment:4>
Tor Bug Tracker & Wiki <https://trac.torproject.org/>
The Tor Project: anonymity online