SPIGOT-7001: Fix entity already exists in CraftWorld#spawnFallingBlock

By: Doc <nachito94@msn.com>

paper-server/nms-patches/net/minecraft/world/entity/item/EntityFallingBlock.patch

@@ -9,15 +9,26 @@
  public class EntityFallingBlock extends Entity {
  
      private static final Logger LOGGER = LogUtils.getLogger();
-@@ -81,6 +83,7 @@
+@@ -80,10 +82,17 @@
+     }
  
      public static EntityFallingBlock fall(World world, BlockPosition blockposition, IBlockData iblockdata) {
++        // CraftBukkit start
++        return fall(world, blockposition, iblockdata, false);
++    }
++
++    public static EntityFallingBlock fall(World world, BlockPosition blockposition, IBlockData iblockdata, boolean isCustom) {
++        // CraftBukkit end
          EntityFallingBlock entityfallingblock = new EntityFallingBlock(world, (double) blockposition.getX() + 0.5D, (double) blockposition.getY(), (double) blockposition.getZ() + 0.5D, iblockdata.hasProperty(BlockProperties.WATERLOGGED) ? (IBlockData) iblockdata.setValue(BlockProperties.WATERLOGGED, false) : iblockdata);
 +        if (CraftEventFactory.callEntityChangeBlockEvent(entityfallingblock, blockposition, iblockdata.getFluidState().createLegacyBlock()).isCancelled()) return entityfallingblock; // CraftBukkit
  
          world.setBlock(blockposition, iblockdata.getFluidState().createLegacyBlock(), 3);
-         world.addFreshEntity(entityfallingblock);
+-        world.addFreshEntity(entityfallingblock);
-@@ -166,6 +169,12 @@
++        world.addFreshEntity(entityfallingblock, (isCustom) ? org.bukkit.event.entity.CreatureSpawnEvent.SpawnReason.CUSTOM : org.bukkit.event.entity.CreatureSpawnEvent.SpawnReason.DEFAULT); // CraftBukkit - keep logic in SpawnReason if the method is use by API
+         return entityfallingblock;
+     }
+ 
+@@ -166,6 +175,12 @@
                                      this.blockState = (IBlockData) this.blockState.setValue(BlockProperties.WATERLOGGED, true);
                                  }
  
@@ -30,7 +41,7 @@
                                  if (this.level.setBlock(blockposition, this.blockState, 3)) {
                                      ((WorldServer) this.level).getChunkSource().chunkMap.broadcast(this, new PacketPlayOutBlockChange(blockposition, this.level.getBlockState(blockposition)));
                                      this.discard();
-@@ -236,7 +245,7 @@
+@@ -236,7 +251,7 @@
              if (i < 0) {
                  return false;
              } else {
@@ -39,7 +50,7 @@
                  DamageSource damagesource1;
  
                  if (this.blockState.getBlock() instanceof Fallable) {
-@@ -252,7 +261,9 @@
+@@ -252,7 +267,9 @@
                  float f2 = (float) Math.min(MathHelper.floor((float) i * this.fallDamagePerDistance), this.fallDamageMax);
  
                  this.level.getEntities((Entity) this, this.getBoundingBox(), predicate).forEach((entity) -> {

paper-server/src/main/java/org/bukkit/craftbukkit/CraftWorld.java

@@ -1145,22 +1145,16 @@ public class CraftWorld extends CraftRegionAccessor implements World {
         Validate.notNull(material, "Material cannot be null");
         Validate.isTrue(material.isBlock(), "Material must be a block");
 
-        EntityFallingBlock entity = EntityFallingBlock.fall(world, new BlockPosition(location.getX(), location.getY(), location.getZ()), CraftMagicNumbers.getBlock(material).defaultBlockState());
+        EntityFallingBlock entity = EntityFallingBlock.fall(world, new BlockPosition(location.getX(), location.getY(), location.getZ()), CraftMagicNumbers.getBlock(material).defaultBlockState(), true);
-        entity.time = 1;
-
-        world.addFreshEntity(entity, SpawnReason.CUSTOM);
         return (FallingBlock) entity.getBukkitEntity();
     }
 
     @Override
     public FallingBlock spawnFallingBlock(Location location, BlockData data) throws IllegalArgumentException {
         Validate.notNull(location, "Location cannot be null");
-        Validate.notNull(data, "Material cannot be null");
+        Validate.notNull(data, "BlockData cannot be null");
 
-        EntityFallingBlock entity = EntityFallingBlock.fall(world, new BlockPosition(location.getX(), location.getY(), location.getZ()), ((CraftBlockData) data).getState());
+        EntityFallingBlock entity = EntityFallingBlock.fall(world, new BlockPosition(location.getX(), location.getY(), location.getZ()), ((CraftBlockData) data).getState(), true);
-        entity.time = 1;
-
-        world.addFreshEntity(entity, SpawnReason.CUSTOM);
         return (FallingBlock) entity.getBukkitEntity();
     }