EditPrefs should be just a wrapper around the action of changing prefs,
but someone had added a side effect of calling Login() sometimes. The
side effect happened *after* running the state machine, which would
sometimes result in us going into NeedsLogin immediately before calling
cc.Login().
This manifested as the macOS app not being able to Connect if you
launched it with LoggedOut=false and WantRunning=false. Trying to
Connect() would sent us to the NeedsLogin state instead.
Signed-off-by: Avery Pennarun <apenwarr@tailscale.com>
A very long unit test that verifies the way the controlclient and
ipn.Backend interact.
This is a giant sequential test of the state machine. The test passes,
but only because it's asserting all the wrong behaviour. I marked all
the behaviour I think is wrong with BUG comments, and several
additional test opportunities with TODO.
Note: the new test supercedes TestStartsInNeedsLoginState, which was
checking for incorrect behaviour (although the new test still checks
for the same incorrect behaviour) and assumed .Start() would converge
before returning, which it happens to do, but only for this very
specific case, for the current implementation. You're supposed to wait
for the notifications.
Updates: tailscale/corp#1660
Signed-off-by: Avery Pennarun <apenwarr@tailscale.com>