Fix NPE in AnvilDamageEvent - Closes #1331

Spigot-Server-Patches/AnvilDamageEvent.patch

@@ -5,7 +5,7 @@ Subject: [PATCH] AnvilDamageEvent
 
 
 diff --git a/src/main/java/net/minecraft/server/ContainerAnvil.java b/src/main/java/net/minecraft/server/ContainerAnvil.java
-index fb3413d81e..9f20348d0c 100644
+index fb3413d81e..3b23ef9863 100644
 --- a/src/main/java/net/minecraft/server/ContainerAnvil.java
 +++ b/src/main/java/net/minecraft/server/ContainerAnvil.java
 @@ -0,0 +0,0 @@ public class ContainerAnvil extends Container {
@@ -13,7 +13,7 @@ index fb3413d81e..9f20348d0c 100644
                      if (!entityhuman.abilities.canInstantlyBuild && iblockdata.a(TagsBlock.y) && entityhuman.getRandom().nextFloat() < 0.12F) {
                          IBlockData iblockdata1 = BlockAnvil.a_(iblockdata);
 +                        // Paper start
-+                        com.destroystokyo.paper.event.block.AnvilDamagedEvent event = new com.destroystokyo.paper.event.block.AnvilDamagedEvent(getBukkitView(), org.bukkit.craftbukkit.block.data.CraftBlockData.fromData(iblockdata1));
++                        com.destroystokyo.paper.event.block.AnvilDamagedEvent event = new com.destroystokyo.paper.event.block.AnvilDamagedEvent(getBukkitView(), iblockdata1 != null ? org.bukkit.craftbukkit.block.data.CraftBlockData.fromData(iblockdata1) : null);
 +                        if (!event.callEvent()) {
 +                            return itemstack;
 +                        } else if (event.getDamageState() == com.destroystokyo.paper.event.block.AnvilDamagedEvent.DamageState.BROKEN) {