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

--- a/net/minecraft/world/level/block/BlockDirtSnowSpreadable.java
+++ b/net/minecraft/world/level/block/BlockDirtSnowSpreadable.java
@@ -42,6 +42,11 @@
     @Override
     public void tick(IBlockData iblockdata, WorldServer worldserver, BlockPosition blockposition, Random random) {
         if (!b(iblockdata, (IWorldReader) worldserver, blockposition)) {
+            // CraftBukkit start
+            if (org.bukkit.craftbukkit.event.CraftEventFactory.callBlockFadeEvent(worldserver, blockposition, Blocks.DIRT.getBlockData()).isCancelled()) {
+                return;
+            }
+            // CraftBukkit end
             worldserver.setTypeUpdate(blockposition, Blocks.DIRT.getBlockData());
         } else {
             if (worldserver.getLightLevel(blockposition.up()) >= 9) {
@@ -51,7 +56,7 @@
                     BlockPosition blockposition1 = blockposition.c(random.nextInt(3) - 1, random.nextInt(5) - 3, random.nextInt(3) - 1);
 
                     if (worldserver.getType(blockposition1).a(Blocks.DIRT) && c(iblockdata1, (IWorldReader) worldserver, blockposition1)) {
-                        worldserver.setTypeUpdate(blockposition1, (IBlockData) iblockdata1.set(BlockDirtSnowSpreadable.SNOWY, worldserver.getType(blockposition1.up()).a(Blocks.SNOW)));
+                        org.bukkit.craftbukkit.event.CraftEventFactory.handleBlockSpreadEvent(worldserver, blockposition, blockposition1, (IBlockData) iblockdata1.set(BlockDirtSnowSpreadable.SNOWY, worldserver.getType(blockposition1.up()).a(Blocks.SNOW))); // CraftBukkit
                     }
                 }
             }