SPIGOT-4943: Zombie villager conversion player API.

Also resetting the conversion player when stopping a conversion.

nms-patches/EntityZombieVillager.patch

@@ -1,6 +1,6 @@
 --- a/net/minecraft/server/EntityZombieVillager.java
 +++ b/net/minecraft/server/EntityZombieVillager.java
-@@ -3,6 +3,10 @@
+@@ -3,15 +3,20 @@
  import com.mojang.datafixers.Dynamic;
  import java.util.UUID;
  import javax.annotation.Nullable;
@@ -11,8 +11,11 @@
  
  public class EntityZombieVillager extends EntityZombie implements VillagerDataHolder {
  
-@@ -12,6 +16,7 @@
+     public static final DataWatcherObject<Boolean> CONVERTING = DataWatcher.a(EntityZombieVillager.class, DataWatcherRegistry.i);
-     private UUID conversionPlayer;
+     private static final DataWatcherObject<VillagerData> c = DataWatcher.a(EntityZombieVillager.class, DataWatcherRegistry.q);
+     public int conversionTime;
+-    private UUID conversionPlayer;
++    public UUID conversionPlayer; // CraftBukkit - public
      private NBTTagCompound bB;
      private int bC;
 +    private int lastTick = MinecraftServer.currentTick; // CraftBukkit - add field

src/main/java/org/bukkit/craftbukkit/entity/CraftVillagerZombie.java

@@ -7,6 +7,8 @@ import net.minecraft.server.EntityZombieVillager;
 import net.minecraft.server.IRegistry;
 import net.minecraft.server.MinecraftKey;
 import org.apache.commons.lang.Validate;
+import org.bukkit.Bukkit;
+import org.bukkit.OfflinePlayer;
 import org.bukkit.craftbukkit.CraftServer;
 import org.bukkit.entity.EntityType;
 import org.bukkit.entity.Villager;
@@ -62,8 +64,20 @@ public class CraftVillagerZombie extends CraftZombie implements ZombieVillager {
             getHandle().conversionTime = -1;
             getHandle().getDataWatcher().set(EntityZombieVillager.CONVERTING, false);
             getHandle().persistent = false; // CraftBukkit - SPIGOT-4684 update persistence
+            getHandle().conversionPlayer = null;
         } else {
             getHandle().startConversion((UUID) null, time);
         }
     }
+
+    @Override
+    public OfflinePlayer getConversionPlayer() {
+        return (getHandle().conversionPlayer == null) ? null : Bukkit.getOfflinePlayer(getHandle().conversionPlayer);
+    }
+
+    @Override
+    public void setConversionPlayer(OfflinePlayer conversionPlayer) {
+        if (!this.isConverting()) return;
+        getHandle().conversionPlayer = (conversionPlayer == null) ? null : conversionPlayer.getUniqueId();
+    }
 }