No-one becomes a leader after netsplit

[kzemek]

I found an unexpected behaviour of locks_leaders; I confirmed it using test_cb.erl. The repro is very simple:

1. start test_cb on nodes A and B; each process is a leader
2. connect A with B; one of test_cb processes will become the leader
3. disconnect A and B; each process is a leader again
4. connect A with B; both processes will be "elected" at the same time, after which both will surrender.

test_cb node A logs
test_cb node B logs

[uwiger]

Indeed. I've pushed a fix, which also has a test for the 2-node case. I verified that it failed before, and it seems to pass with the last commit - see PR #26

[kzemek]

Seems to work for me. After updating to locks from the new branch I had one case where both leaders surrendered after the first connection (no netsplit in the meantime); I recompiled immediately and couldn't reproduce it after.

[uwiger]

Ok, I've merged the PR. Thanks for your help!