Problem/Bug Attribute LootTableSeed missing for generated containers with attached LootTable

I recently noticed that containers with attached LootTables in structures no longer store the LootTableSeed attribute, which results in non deterministic container content(when recreating a world with the same seed and reopening the same chest its contents will be different, which isn't vanilla behaviour).

I first noticed the bug in 1.20.2 builds for paper but the current spigot and craftbukkit builds show the same behaviour, while the vanilla client/server still stores the LootTableSeed. So i would assume the bug was introduced by bukkit/craftbukkit.

Steps to reproduce:

• Generate a new world using the newest craftbukkit 1.20.2 jar
• find a structure with containers
• Pick one container(without opening it)
• Save the world
• Open the corresponding region file and search for the container
• The container has the LootTable attribute attached, but is missing the LootTableSeed attribute

When recreating these steps on a vanilla 1.20.2 server the LootTableSeed attribute is present.

For some additional context:
The bug was introduced to paper in https://github.com/PaperMC/paper/commit/4cdbb0c86c40f5ff93a9a7cdca3102636b35b6d4(1.20 build #204 still works, while 1.20 build #205 doesn't), so one of the merged changes will be its cause. I don't seem to be able to find old craftbukkit or spigot builds, so i'm unable to pin it down any further.

 

No, not yet.
How is paper involved if it also occurs in the craftbukkit and spigot builds? Don't they merge craftbukkit and spigot changes into their project?