MC-276625Strider spawning freezes the server when the empty fluid is in the lava tag
A data pack that adds the minecraft:empty fluid to the #minecraft:lava fluid tag will cause the game to freeze when attempting to spawn a strider.
Steps to reproduce
1. Load a data pack with a #minecraft:lava fluid tag containing the minecraft:empty fluid. An example data pack is attached.
2. Visit the Nether: /execute in minecraft:the_nether run tp @s ~ 100 ~
3. Move around until in a location where striders would normally spawn.
4. Observe that the server is now frozen.
Code analysis (Yarn mappings)
A loop is controlled by a tag in the StriderEntity.canSpawn method, which allows out-of-world positions to satisfy the condition and infinitely move the position up:
public static boolean canSpawn(EntityType<StriderEntity> type, WorldAccess world, SpawnReason spawnReason, BlockPos pos, Random random) { BlockPos.Mutable mutablePos = pos.mutableCopy(); do { mutablePos.move(Direction.UP); } while (world.getFluidState(mutablePos).isIn(FluidTags.LAVA)); return world.getBlockState(mutablePos).isAir(); }
A suggested fix would be to add an additional condition for the world top Y position to this loop.
Created Issue:
Strider spawning freezes the server when the empty fluid is in the lava tag
A data pack that adds the minecraft:empty fluid to the #minecraft:lava fluid tag will cause the game to freeze when attempting to spawn a strider.
Steps to reproduce
1. Load a data pack with a #minecraft:lava fluid tag containing the minecraft:empty fluid.
2. Visit the Nether: /execute in minecraft:the_nether run tp @s ~ ~ ~
3. Move around until in a location where striders would normally spawn.
4. Observe that the server is now frozen.Code analysis (Yarn mappings)
A loop is controlled by a tag in the StriderEntity.canSpawn method, which allows out-of-world positions to satisfy the condition and infinitely move the position up:
public static boolean canSpawn(EntityType<StriderEntity> type, WorldAccess world, SpawnReason spawnReason, BlockPos pos, Random random) { BlockPos.Mutable mutablePos = pos.mutableCopy(); do { mutablePos.move(Direction.UP); } while (world.getFluidState(mutablePos).isIn(FluidTags.LAVA)); return world.getBlockState(mutablePos).isAir(); }A suggested fix would be to add an additional condition for the world top Y position to this loop.
![[Mod] Les3awe](../../../data/avatars/users/79847.png){kind=small}
![[Mojang] Triage Team](../../../data/avatars/users/89842.png){kind=small}
Normal![[Bot] Arisa](../../../data/avatars/users/43007.png){kind=small}
A data pack that adds the minecraft:empty fluid to the #minecraft:lava fluid tag will cause the game to freeze when attempting to spawn a strider.
Steps to reproduce
1. Load a data pack with a #minecraft:lava fluid tag containing the minecraft:empty fluid.
2. Visit the Nether: /execute in minecraft:the_nether run tp @s ~~~
3. Move around until in a location where striders would normally spawn.
4. Observe that the server is now frozen.Code analysis (Yarn mappings)
A loop is controlled by a tag in the StriderEntity.canSpawn method, which allows out-of-world positions to satisfy the condition and infinitely move the position up:
public static boolean canSpawn(EntityType<StriderEntity> type, WorldAccess world, SpawnReason spawnReason, BlockPos pos, Random random) { BlockPos.Mutable mutablePos = pos.mutableCopy(); do { mutablePos.move(Direction.UP); } while (world.getFluidState(mutablePos).isIn(FluidTags.LAVA)); return world.getBlockState(mutablePos).isAir(); }A suggested fix would be to add an additional condition for the world top Y position to this loop.
A data pack that adds the minecraft:empty fluid to the #minecraft:lava fluid tag will cause the game to freeze when attempting to spawn a strider.
Steps to reproduce
1. Load a data pack with a #minecraft:lava fluid tag containing the minecraft:empty fluid. An example data pack is attached.
2. Visit the Nether: /execute in minecraft:the_nether run tp @s ~ 100 ~
3. Move around until in a location where striders would normally spawn.
4. Observe that the server is now frozen.Code analysis (Yarn mappings)
A loop is controlled by a tag in the StriderEntity.canSpawn method, which allows out-of-world positions to satisfy the condition and infinitely move the position up:
public static boolean canSpawn(EntityType<StriderEntity> type, WorldAccess world, SpawnReason spawnReason, BlockPos pos, Random random) { BlockPos.Mutable mutablePos = pos.mutableCopy(); do { mutablePos.move(Direction.UP); } while (world.getFluidState(mutablePos).isIn(FluidTags.LAVA)); return world.getBlockState(mutablePos).isAir(); }A suggested fix would be to add an additional condition for the world top Y position to this loop.
![[Mod] Jarl-Penguin](../../../data/avatars/users/92849.png){kind=small}
![[Mojang] etanaratsastaja](../../../data/avatars/users/10122.svg){kind=small}
[Mojang] etanaratsastaja[Mojang] etanaratsastaja
I wasn't able to reproduce this in our latest snapshots, could you give it another go?
I was able to reproduce again in Minecraft snapshot 24w40a. I've attached the data pack I used to test as well as what the game looks like after the freeze occurs - I hope this helps in reproducing the issue.
Can confirm in 24w40a