PaperMC/patches/server/0621-prevent-unintended-light-block-manipulation.patch
Bjarne Koll c5a10665b8
Remove wall-time / unused skip tick protection (#11412)
Spigot still maintains some partial implementation of "tick skipping", a
practice in which the MinecraftServer.currentTick field is updated not
by an increment of one per actual tick, but instead set to
System.currentTimeMillis() / 50. This behaviour means that the tracked
tick may "skip" a tick value in case a previous tick took more than the
expected 50ms.

To compensate for this in important paths, spigot/craftbukkit
implements "wall-time". Instead of incrementing/decrementing ticks on
block entities/entities by one for each call to their tick() method,
they instead increment/decrement important values, like
an ItemEntity's age or pickupDelay, by the difference of
`currentTick - lastTick`, where `lastTick` is the value of
`currentTick` during the last tick() call.

These "fixes" however do not play nicely with minecraft's simulation
distance as entities/block entities implementing the above behaviour
would "catch up" their values when moving from a non-ticking chunk to a
ticking one as their `lastTick` value remains stuck on the last tick in
a ticking chunk and hence lead to a large "catch up" once ticked again.

Paper completely removes the "tick skipping" behaviour (See patch
"Further-improve-server-tick-loop"), making the above precautions
completely unnecessary, which also rids paper of the previous described
incompatibility with non-ticking chunks.
2024-09-19 16:36:07 +02:00

25 lines
1.7 KiB
Diff

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Jake Potrebic <jake.m.potrebic@gmail.com>
Date: Mon, 13 Sep 2021 18:55:45 -0700
Subject: [PATCH] prevent unintended light block manipulation
diff --git a/src/main/java/net/minecraft/world/level/block/LightBlock.java b/src/main/java/net/minecraft/world/level/block/LightBlock.java
index 01722473a4861533dba0ab6edf3982c0278c41e1..2b3c395529a15c9f07a4c0cff7f82199298bcb6d 100644
--- a/src/main/java/net/minecraft/world/level/block/LightBlock.java
+++ b/src/main/java/net/minecraft/world/level/block/LightBlock.java
@@ -49,6 +49,14 @@ public class LightBlock extends Block implements SimpleWaterloggedBlock {
builder.add(LEVEL, WATERLOGGED);
}
+ // Paper start - prevent unintended light block manipulation
+ @Override
+ protected net.minecraft.world.ItemInteractionResult useItemOn(final ItemStack stack, final BlockState state, final Level world, final BlockPos pos, final Player player, final net.minecraft.world.InteractionHand hand, final BlockHitResult hit) {
+ if (player.getItemInHand(hand).getItem() != Items.LIGHT || !player.mayInteract(world, pos) || !player.mayUseItemAt(pos, hit.getDirection(), player.getItemInHand(hand))) { return net.minecraft.world.ItemInteractionResult.SKIP_DEFAULT_BLOCK_INTERACTION; } // Paper - Prevent unintended light block manipulation
+ return super.useItemOn(stack, state, world, pos, player, hand, hit);
+ }
+ // Paper end - prevent unintended light block manipulation
+
@Override
protected InteractionResult useWithoutItem(BlockState state, Level world, BlockPos pos, Player player, BlockHitResult hit) {
if (!world.isClientSide && player.canUseGameMasterBlocks()) {