PaperMC/paper-server/nms-patches/net/minecraft/world/level/block/SculkVeinBlock.patch

--- a/net/minecraft/world/level/block/SculkVeinBlock.java
+++ b/net/minecraft/world/level/block/SculkVeinBlock.java
@@ -108,10 +108,11 @@
 
     @Override
     public int attemptUseCharge(SculkSpreader.a sculkspreader_a, GeneratorAccess generatoraccess, BlockPosition blockposition, RandomSource randomsource, SculkSpreader sculkspreader, boolean flag) {
-        return flag && this.attemptPlaceSculk(sculkspreader, generatoraccess, sculkspreader_a.getPos(), randomsource) ? sculkspreader_a.getCharge() - 1 : (randomsource.nextInt(sculkspreader.chargeDecayRate()) == 0 ? MathHelper.floor((float) sculkspreader_a.getCharge() * 0.5F) : sculkspreader_a.getCharge());
+        // CraftBukkit - add source block
+        return flag && this.attemptPlaceSculk(sculkspreader, generatoraccess, sculkspreader_a.getPos(), randomsource, blockposition) ? sculkspreader_a.getCharge() - 1 : (randomsource.nextInt(sculkspreader.chargeDecayRate()) == 0 ? MathHelper.floor((float) sculkspreader_a.getCharge() * 0.5F) : sculkspreader_a.getCharge());
     }
 
-    private boolean attemptPlaceSculk(SculkSpreader sculkspreader, GeneratorAccess generatoraccess, BlockPosition blockposition, RandomSource randomsource) {
+    private boolean attemptPlaceSculk(SculkSpreader sculkspreader, GeneratorAccess generatoraccess, BlockPosition blockposition, RandomSource randomsource, BlockPosition sourceBlock) { // CraftBukkit
         IBlockData iblockdata = generatoraccess.getBlockState(blockposition);
         TagKey<Block> tagkey = sculkspreader.replaceableBlocks();
         Iterator iterator = EnumDirection.allShuffled(randomsource).iterator();
@@ -126,7 +127,11 @@
                 if (iblockdata1.is(tagkey)) {
                     IBlockData iblockdata2 = Blocks.SCULK.defaultBlockState();
 
-                    generatoraccess.setBlock(blockposition1, iblockdata2, 3);
+                    // CraftBukkit start - Call BlockSpreadEvent
+                    if (!org.bukkit.craftbukkit.event.CraftEventFactory.handleBlockSpreadEvent(generatoraccess, sourceBlock, blockposition1, iblockdata2, 3)) {
+                        return false;
+                    }
+                    // CraftBukkit end
                     Block.pushEntitiesUp(iblockdata1, iblockdata2, generatoraccess, blockposition1);
                     generatoraccess.playSound((EntityHuman) null, blockposition1, SoundEffects.SCULK_BLOCK_SPREAD, SoundCategory.BLOCKS, 1.0F, 1.0F);
                     this.veinSpreader.spreadAll(iblockdata2, generatoraccess, blockposition1, sculkspreader.isWorldGeneration());