Taking out leader as queued action still allows AI nations to carry out actions
If you happen to take out another nation's leader as the result of a queued action, meaning the unit has no additional movement points for the rest of the turn and using go to or just click and drag to the destination, (ie: nuke the city containing the leader or using an Air/Sea Unit which can't occupy the city to finish off the leader), despite the message saying the AI nation has lost the game, the nation's cities and units themselves don't disappear until the very end of the turn (after all other calculations are done). I didn't check to see if the nation which was defeated had their units move and take actions, but it was interesting that an allied nation who had shared vision was able to take over vanquished nation's empty city (and for some reason I didn't understand resent me for nuking the city), because if that happened during the player turn, the vanquished nation's troops and cities just disappears immediately.
The save game in #44419 (just build a nuke and nuke any capital of any other nation as a queued action and watch the AI teammate occupy the city before the nation's assets completely disappears)
Also, while a separate but related issue, in a supermajority of cases in the games I played, I notice the the AI tends to keep their leader unit in their capital, making it very easy to take them out for players who can focus on getting their forces (ie: fully loaded aircraft carrier with bombers and fighters or just a missiles and some sea units as an escort or sneaking a nuke or a fully loaded submarine with cruise missiles into range). Even randomly moving the leader around between fortified cities is a safer choice (unless the city is under constant attack by enemy diplomats/spies)
It's yet another aspect of a problem risen in #44284: kill_dying_players() is called too rare. But calling it immediately after a leader is killed will require checks if players dealed with are alive in such a lot of code that we are not ready to and possibly not willing to do. Maybe we should just add yet another k_d_p() call after unit orders execution sub-phase.