[tor-bugs] #19875 [Core Tor/Tor]: shuffle our bridges when we load them from config

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#19875: shuffle our bridges when we load them from config
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 Reporter:  arma          |          Owner:
     Type:  enhancement   |         Status:  new
 Priority:  Medium        |      Milestone:  Tor: 0.2.???
Component:  Core Tor/Tor  |        Version:
 Severity:  Normal        |     Resolution:
 Keywords:  easy          |  Actual Points:
Parent ID:                |         Points:
 Reviewer:                |        Sponsor:
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Comment (by isis):

 Replying to [comment:3 hdevalence]:
 > Hi, a first patch is here:
 https://code.ciph.re/hdevalence/tor/commit/4fda92e51bc5c69f5ba4c19c22184a1e0b87d9c1
 >
 > I'm not really sure what the right way to write a test for it is -- the
 description of the intended behaviour above relies on a bunch of other
 parts of tor behaving in a certain way (e.g., interaction with the
 statefile).  Testing just that `shuffle_bridge_list()` actually shuffles
 the list doesn't ensure the behaviour in the top of the ticket -- is that
 OK?

 Tor's testing/mocking system takes a tiny bit of learning, but not too
 much. I'm happy to help you write tests, or write them for you if you'd
 prefer to move on to working on something else.

 > Also, should this behaviour be configurable, instead of always-on?  Do
 people rely on bridge ordering?

 It seems like a good idea to make it configurable, but off-by-default.
 This way, we can preserve the currently expected behaviour without
 surprising users. We can revert my patch in #18113 and just flip the
 config variable on for TB users, and, likewise, non-TB users who really
 want this can opt-in to enabling it.

 (I'm willing to be talked out of this viewpoint if there's good reason to
 do otherwise.)

 Regardless of whether it should be on or off by default, it seems like
 it's probably a good idea to have a config variable.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/19875#comment:5>
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