Globally visible tech
Make it possible to mark a tech such that everyone in the world knows that someone has researched it even if they aren't in contact with the player that has researched it. One possible implementation is to use a tech flag.
My motivation is to make a wonder switching effect on the discovery of some tech more user friendly. I can't make the tech obsolete the wonder as that would make the wonder invisible for the requirement system even if survives is true. An alternative solution is to make each player's discovery of the tech switch the global effects of the wonder but only for than player.
A tech with the "Globally Visible" flag's non survives world range requirements behaves like the current default for surviving world rannge requirements.
What player has the tech with the "Globally Visible" flag is visible to those that see him. This allows tech theft of a globally visible tech possible even if the spy's owner can't see the non globally visible techs of the victim.
Isn't it a bug that building obsoletion changes "survives" req? I think, by logic it would fire if the player has ever owned a building with this effect active. Well, for some more complicated obsoletion reqs we should check it more often than at building finishing and city transfer to work as expected to be sure, and still can miss a minute owning...
Reply To ihnatus
Isn't it a bug that building obsoletion changes "survives" req? I think, by logic it would fire if the player has ever owned a building with this effect active.
This was my fist instinct too but it may have been intentional. A ruleset may wish to check if a non obsolete wonder was built but has been destroyed. I'm not opposed to considering this a bug and going for the more logical approach.