Per-campaign settings are restored after the world is deserialized

[Suor]

world_state.onDeserialize restores per-campaign settings after __original(_in):

q.onDeserialize = @(__original) function( _in )
{
    __original(_in);   // World.Flags, EntityManager, rosters, every item_container
    ...
    ::MSU.System.ModSettings.flagDeserialize(_in);
}

onSerialize is the mirror image — it calls flagSerialize(_out) before __original.

So for the whole duration of world deserialization a per-campaign setting still holds the
global value from ModSettings.sav. Any mod that reads a setting from a hook reachable
during load sees the wrong value.

Concrete case: Challenges mod hooks item_container.equip and refuses items banned by a setting, i.e. "only light shields". This causes the shield to go off a bro to stash on game load. Campaign has the setting at "allow all shields", which is only read after. In-session load is fine, since the setting object already holds the campaign value. However, if you load other campaign from within already loaded one it may break in even more surprising manner.

I realise ::World.Flags only exists after World.Flags.onDeserialize(_in), which is the
first line inside __original, so the read can't simply move up — it would need a
finer-grained hook that runs between World.Flags and EntityManager.

Workaround for mod authors, for the record: guard on ::MSU.Serialization.isLoading().

MSU 1.9.0, also present on master.

[LordMidas]

I am planning to change how MSU saves settings. Instead of saving all settings into the world flags, and restoring all of them on loading a save game, I think we should only save "NewCampaign" and "NewCampaignOnly" settings. This whole concept of saving settings in world flags is an old system before we had persistent data.

Now that we have persistent data, users can save settings on the main menu. And then it behaves like normal games i.e. you set settings on main menu and they apply to all your games and if you modify a setting during a game then it gets saved and continues to apply to all campaigns until you change it.

Only "NewCampaign" and "NewCampaignOnly" settings should be saved into world flags because they can contain information relevant for that campaign.

Do you foresee any problems with us implementing this change?

[Suor]

Yeah, I forsee it breaking almost all mods using MSU options in case someone plays several campaign intermixed with different settings. I.e. I have different ways to set up Challenges mod every time, and some other mods like Bro Studio and Elite Few. Unless those will use Campaign or Campaign only settings

This will also create a lot of confusion, i.e. one needs to remember, which options are witch.

[Suor]

Also if you'll need to set up all the campaign and campaign only setting every time, because they not saved globally that would be very annoying. I'm pretty annoyed by vanilla not saving difficulty and map settings, and there are only 5 of them.