Gifted capital keeps Imperial Palace and Military Command with associated benefits to the giftee

[Blue-Award]

Bug Report

Environment

• FreeOrion Version: 2022-11-01.6387e2e i.e. the MP22 version
• Fetched as
  • Weekly development build

Description

You can gift planets to your ally or person at peace. In anticipation of what may happen (and has happened) in slow multiplayer game 22, I've tested it and it perhaps surprisingly turns out you can gift your capital. Not sure if that's something expected. But what is certainly not expected is that this gifting process does not destroy the supposedly unique buildings like Military Command and the Imperial Palace. Those buildings continue to provide their functionality. Extra Imperial Palace even grants extra Economic Policy slot, and extra Military Command grants extra military policy slot.

So this is exploitable between allied/peaceful empires to farm the buildings like imperial palace or military command and associated benefits including slots.

This is evidenced now in MP22, turn 84 onwards

Expected Result

I think I would expect Military Command and Imperial Palace to be destroyed upon gifting, at least if the gifted empire already has a copy of such building on its own turf.

Perhaps go as far as disallow gifting your capital? (or otherwise losing it intentionally though I suppose people like their scorched earth tactics)

Not sure about Automated History Analyser. I think it is expected for Cultural Archives to stay upon conquest so presumably also upon gifting. And since AHA can be built where Cultural Archives are, then perhaps it would be fine to leave it

Steps to reproduce

Start a multiplayer game locally on a small map for fast reproduction, with two clients/people. Ally each other or make peace. With one empire, go to the capital of other empire using some ship. Gift the capital.

It has happened in current MP22, turn 84 onwards, Moskva a planet. o01eg can confirm without controversy as he is ally of Daybreak, who now owns Moskva a and has extra economic policy thanks to that, and maybe military one too? Plus the research benefits of Automatic History Analyser.

EDIT: also added savegame from my local reproduction of the issue savegame

[Blue-Award]

OK I've reproduced it locally and checked that you also get extra military slot for extra military command, attaching saves before gifting (turn 14) and after gifting (turn 15)
savegame.zip

[Blue-Award]

I suppose military slots are easier to multiply if you exploit this, as one can build Military Command anywhere without more serious hit of losing one's capital

[Blue-Award]

From what LienRag is saying, this may affect Interspecies Design Academy as well, as it is at least not destroyed as a principle upon gifting. But not sure if those are destroyed if they would violate their rules or not. Perhaps worth checking Imperial Regional Administration as well.

I suppose one can argue buildings are ok to stay upon gifting if they do not violate any rules, so Military Command could in theory stay unless giftee already had one, and actually Imperial Palace as well.

Another question is how conquest behaves with regard to such buildings. Is Military Command / Imperial Palace destroyed just as a principle upon conquest, or only if they would violate the rules had they stayed with the victor? Should conquest behave differently than gifting in this regard?

[geoffthemedio]

Is Military Command / Imperial Palace destroyed just as a principle upon conquest

Should be, given the specified capture results:
https://github.com/freeorion/freeorion/blob/master/default/scripting/buildings/MILITARY_COMMAND.focs.txt#L4
https://github.com/freeorion/freeorion/blob/master/default/scripting/buildings/IMPERIAL_PALACE.focs.txt#L4

[geoffthemedio]

most of this should be resolved by 0a4c7b1, 900f680, and a5311dd

[geoffthemedio]

Is this sufficiently resolved?