Originally, the PlayerSkill packet contained skills, attribute increases and level progress. In 78441c769a, the attribute increases were moved to the PlayerAttribute packet and the level progress was moved to the PlayerLevel packet, but – due to an oversight – attribute increases and level progress were still being applied to the local player only when a PlayerSkill packet was received, based on whatever values were stored from the last PlayerAttribute and PlayerLevel packets.
Previously, when recharging or repairing an item, the client sent a PlayerInventory packet to the server with the old version of the item that was supposed to be removed and then it sent a PlayerInventory packet with the new version of the item that was supposed to be added.
Unfortunately, the current CoreScripts make it so custom items using generated IDs have their records deleted when they are completely removed from the world, however briefly, even if they are added back immediately afterwards. In practice, this meant that – before this commit – recharging or repairing a custom item led to its removal from the player inventory stored on the server, followed by the deletion of its record, followed by its readdition to the inventory (but with the record staying deleted). Logging out and logging back in immediately prevented the player from receiving the item anymore because of its now non-existent record.
Previously, multiple stacks of the same item ID could overwrite data in each other because of how the logic in ContainerStore::add() works. For example, a stack of 5 grand soul gems with no souls would get added to the player, then the attempt to add a grand soul gem with a particular soul would retrieve the previous stack first before setting all of it to that soul, resulting in 6 grand soul gems with that soul.
Previously, unstacking items for a player led to a PlayerInventory packet being sent about the items' removal.
This change makes it so both a packet about their re-addition and their removal are sent instead, cancelling each other out, which is inelegant, but arguably preferable to complicating the sending of PlayerInventory packets again.