percona/percona-pacemaker-agents — pull request #7 by FrankVanDamme (2014-01-31 15:21:50+00:00)
Title: Added extra check dor new_master: just do "start slave" if it's empty

I put this extra check in the script about a year ago, I'm not sure if by now the condition in question ever occurs again but I thought I'd share it anyway. If the parameter "new_master" is empty, the mysql server may simply remember the last master host, log file, position etc. so a simple "start slave" does the trick.