In Control does not allow other mods to respond to changes it makes to the drops array during firing of LivingDropsEvent

[sam-kirby]

Description

In Control subscribes to the LivingDropsEvent with Lowest priority. This means any drops it adds to the list cannot necessarily be dealt with by other mods. Conversely, drops it removes may already have been handled by another mod.

Example

Astral Sorcery has a perk which causes all drops from LivingDropsEvent to go into your inventory (https://github.com/HellFirePvP/AstralSorcery/blob/1.12.2/src/main/java/hellfirepvp/astralsorcery/common/constellation/perk/tree/nodes/key/KeyMagnetDrops.java#L43-L64)

It also subscribes with Lowest priority. Forge selects Astral's handler first. Any drops in the list at this point are added to the player's inventory, including any which would later be removed by In Control.

In Control's handler is later called, there is nothing to remove at this stage so it adds drops which are then placed on the ground.

DarkPacks/SevTech-Ages#3847

Possible Resolution

Anything subscribing to the event with priority Lowest is likely doing so to consume the final List. It therefore seems reasonable that all modifications should be made before this point.

In Control is making modifications, but as these removals may depend on the actions of other mods in higher priority slots, it seems reasonable to keep it at as low priority as possible. Moving the event subscription to Low priority could be a good compromise.

[McJty]

Whatever solution is chosen here, there will always be a potential for problems. If some other mod also uses 'Low' then In Control might conflict with that. Lowest was chosen to avoid problems with other mods in the past. This is not something I can change now as it will break compatibility. I'm afraid there is no good solution for this