[tor-bugs] #21423 [Core Tor/Tor]: Refactor choose_good_entry_server based on different usecases

[Tor Bug Tracker & Wiki]

#21423: Refactor choose_good_entry_server based on different usecases
------------------------------+--------------------------------
     Reporter:  nickm         |      Owner:
         Type:  defect        |     Status:  new
     Priority:  Medium        |  Milestone:  Tor: 0.3.1.x-final
    Component:  Core Tor/Tor  |    Version:
     Severity:  Normal        |   Keywords:  guards refactor
Actual Points:                |  Parent ID:
       Points:                |   Reviewer:
      Sponsor:                |
------------------------------+--------------------------------
 The choose_good_entry_server function was used in four ways: picking out
 guards for the old (pre-prop271) guard algorithm; picking out guards for
 circuits; picking out guards for testing circuits on non-bridgees; picking
 out entries when entry guards are disabled.  These options should be
 disentangled.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/21423>
Tor Bug Tracker & Wiki <https://trac.torproject.org/>
The Tor Project: anonymity online