[tor-dev] [PATCH] entrynodes.c: Improve readability (issue 9971)

[Martin Kepplinger]

Maybe we can do away with issue 9971 and improve readability:
https://trac.torproject.org/projects/tor/ticket/9971

As response to this mail, I'll append seperate patches for the 3
sub-issues mentioned. They apply (and are build-tested) seperately to
the current tree, so a maintainer can quickly pick one of them up, if
happy with it.

There shouldn't be a conflict in *1* and *2* but I could append a
patchset anyway.

sub-issue *3* is *only* a call for advice and will be written on top of
the other ones, after discussion.

1* rename entry_guard_t's made_contact to used_so_save_if_down
   I think that's readable. Is that about what arma had in mind?

2* rename for_discovery argument of add_an_entry_guard() to
   I like probationary more than provisional. Those 2 are suggested in
   issue 9971.
   I chose forced_probationary for now, because isn't it strictly a
   suboptimal situation
   in terms of desired 'grade of anonymity'. What do you think?

3* NEEDS REVIEW FIRST: regarding the int arguments of
   add_an_entry_guard(). I look at:

   node_t *chosen       is a node to add.
   prepend              is set if the guard should become first in the
                        list?

   there are 2 users of add_an_entry_guard() that pass it a chosen
   node. One is a bridge (prepend) and the other one is a user-defined
   node (!prepend), so:

   Given the fact that the list is not supposed to be long and the two
   'users' are somewhat similar, why not prepend the node if explicitly
   given?