From 2754d7c3b92e8fe5b04fde42fc62fc44c7737bff Mon Sep 17 00:00:00 2001
From: Miles <81843550+Y2Kwastaken@users.noreply.github.com>
Date: Wed, 30 Apr 2025 18:03:40 +0000
Subject: [PATCH] Add Throw EntityChangeBlockEvent for
 BrushableBlockEntity#brush (#12133)

---
 .../entity/BrushableBlockEntity.java.patch    | 62 +++++++++++++++++++
 1 file changed, 62 insertions(+)

diff --git a/paper-server/patches/sources/net/minecraft/world/level/block/entity/BrushableBlockEntity.java.patch b/paper-server/patches/sources/net/minecraft/world/level/block/entity/BrushableBlockEntity.java.patch
index 6f3f6b65d..a71b4f55a 100644
--- a/paper-server/patches/sources/net/minecraft/world/level/block/entity/BrushableBlockEntity.java.patch
+++ b/paper-server/patches/sources/net/minecraft/world/level/block/entity/BrushableBlockEntity.java.patch
@@ -1,5 +1,67 @@
 --- a/net/minecraft/world/level/block/entity/BrushableBlockEntity.java
 +++ b/net/minecraft/world/level/block/entity/BrushableBlockEntity.java
+@@ -65,9 +_,26 @@
+             return false;
+         } else {
+             this.coolDownEndsAtTick = startTick + 10L;
++            // Paper start - EntityChangeBlockEvent
++            // The vanilla logic here is *so* backwards, we'd be moving basically *all* following calls down.
++            // Instead, compute vanilla ourselves up here and just replace the below usages with our computed values for a free diff-on-change.
++            final int currentCompletionStage = this.getCompletionState();
++            final boolean enoughBrushesToBreak = ++this.brushCount >= REQUIRED_BRUSHES_TO_BREAK;
++            final int nextCompletionStage = this.getCompletionState();
++            final boolean differentCompletionStages = currentCompletionStage != nextCompletionStage;
++            final BlockState nextBrokenBlockState = this.getBlockState().setValue(BlockStateProperties.DUSTED, nextCompletionStage);
++            if (enoughBrushesToBreak || differentCompletionStages) {
++                if (!org.bukkit.craftbukkit.event.CraftEventFactory.callEntityChangeBlockEvent(
++                    brusher, this.worldPosition, enoughBrushesToBreak ? computeTurnsTo().defaultBlockState() : nextBrokenBlockState
++                )) {
++                    brushCount--;
++                    return false;
++                }
++            }
++            // Paper end - EntityChangeBlockEvent
+             this.unpackLootTable(level, brusher, stack);
+-            int completionState = this.getCompletionState();
+-            if (++this.brushCount >= 10) {
++            int completionState = currentCompletionStage; // Paper - EntityChangeBlockEvent - use precomputed - diff on change
++            if (enoughBrushesToBreak) { // Paper - EntityChangeBlockEvent - use precomputed - diff on change
+                 this.brushingCompleted(level, brusher, stack);
+                 return true;
+             } else {
+@@ -75,7 +_,7 @@
+                 int completionState1 = this.getCompletionState();
+                 if (completionState != completionState1) {
+                     BlockState blockState = this.getBlockState();
+-                    BlockState blockState1 = blockState.setValue(BlockStateProperties.DUSTED, completionState1);
++                    BlockState blockState1 = nextBrokenBlockState; // Paper - EntityChangeBlockEvent - use precomputed - diff on change
+                     level.setBlock(this.getBlockPos(), blockState1, 3);
+                 }
+ 
+@@ -116,6 +_,11 @@
+         this.dropContent(level, brusher, stack);
+         BlockState blockState = this.getBlockState();
+         level.levelEvent(3008, this.getBlockPos(), Block.getId(blockState));
++    // Paper start - EntityChangeEvent - extract result block logic
++        this.brushingCompleteUpdateBlock(this.computeTurnsTo());
++    }
++    private Block computeTurnsTo() {
++    // Paper end - EntityChangeEvent - extract result block logic
+         Block turnsInto;
+         if (this.getBlockState().getBlock() instanceof BrushableBlock brushableBlock) {
+             turnsInto = brushableBlock.getTurnsInto();
+@@ -123,6 +_,11 @@
+             turnsInto = Blocks.AIR;
+         }
+ 
++    // Paper start - EntityChangeEvent - extract result block logic
++        return turnsInto;
++    }
++    public void brushingCompleteUpdateBlock(final Block turnsInto) {
++    // Paper end - EntityChangeEvent - extract result block logic
+         level.setBlock(this.worldPosition, turnsInto.defaultBlockState(), 3);
+     }
+ 
 @@ -139,7 +_,12 @@
              double d5 = blockPos.getZ() + 0.5 * d1 + d2;
              ItemEntity itemEntity = new ItemEntity(level, d3, d4, d5, this.item.split(level.random.nextInt(21) + 10));