When you are connected to a headless server and become admin, you should remain an admin until you either disconnect/get disconnected or start the game.
However, there is a case where you loose your admin rights when you should not. That's when you are in a highly numbered slot and switch to a map for fewer players where this slot is not available. You remain connected to the server but you loose your admin rights. This also affects r3114 (currently SVN head).
To reproduce:
- start a headless server
- connect to this headless server; you are now its admin
- set the map to Five on Three
- switch to the last available slot (Player 7)
- switch to the next map; if this is an 8 player map, too, then repeat until you hit a map for less than 8 players
- wait three seconds for the new map setting to settle on the server
- you just lost your admin rights, even though you were the only connected player
