[1.2.5] Two of the same art. from Celia's Mausoleum

[breadsmith]

As the title implies, I just received two of the Robes of Force artifact from Celia's Mausoleum, in back to back coffins. While checking to see if this had come up before, I noticed another thread about this and can confirm that we do not have any of the same mods, so I think whatever is doing it is vanilla.

[Radon26]

When spawning an artefacts it always check what artefact has already spawn and what has not.
Even the guaranteed artefacts will not spawn if they already did so in the past.

is it possible that the coffins don't make the check?
or if its somehow predetermined, maybe they make a check when you enter, but not when the coffin is opened?
but hey, that's just a theory... a ToME theory.

[Dao Zeti]

I only skimmed through the lua, but it looks like this: When the level is created, so are the contents of the coffins; when you open the coffin, the content is being added to the level.

When a unique item is added to the level, it is being registered in game.uniques, if I recall right. No more unique items of the same id/definition can be created afterwards. As the items are rolled (created) before, however, in theory every coffin could drop the same unique item. So indead, this is probably an oversight.