Fix FML entity network spawning not using EntityBuilder's facctory. Closes #4845 and #4846

src/main/java/net/minecraftforge/fml/common/network/internal/EntitySpawnHandler.java

@@ -76,7 +76,6 @@ public class EntitySpawnHandler extends SimpleChannelInboundHandler<FMLMessage.E
                     " at ( " + spawnMsg.rawX + "," + spawnMsg.rawY + ", " + spawnMsg.rawZ + ") Please contact mod author or server admin.");
         }
         WorldClient wc = FMLClientHandler.instance().getWorldClient();
-        Class<? extends Entity> cls = er.getEntityClass();
         try
         {
             Entity entity;
@@ -85,7 +84,7 @@ public class EntitySpawnHandler extends SimpleChannelInboundHandler<FMLMessage.E
                 entity = er.doCustomSpawning(spawnMsg);
             } else
             {
-                entity = cls.getConstructor(World.class).newInstance(wc);
+                entity = er.newInstance(wc);
 
                 int offset = spawnMsg.entityId - entity.getEntityId();
                 entity.setEntityId(spawnMsg.entityId);

src/main/java/net/minecraftforge/fml/common/registry/EntityEntryBuilder.java

@@ -276,15 +276,6 @@ public final class EntityEntryBuilder<E extends Entity>
         return entry;
     }
 
-    @Nonnull
-    private EntityRegistry.EntityRegistration createRegistration()
-    {
-        return EntityRegistry.instance().new EntityRegistration(
-            this.mod, this.id, this.entity, this.name, this.network,
-            this.trackingRange, this.trackingUpdateFrequency, this.trackingVelocityUpdates
-        );
-    }
-
     private void registerStatistics()
     {
         if (!this.statisticsRegistered && (this.killEntityStatistic != null && this.entityKilledByStatistic != null))
@@ -340,7 +331,7 @@ public final class EntityEntryBuilder<E extends Entity>
             if (this.added) return;
             this.added = true;
             EntityEntryBuilder.this.registerStatistics();
-            EntityRegistry.instance().insert(EntityEntryBuilder.this.entity, EntityEntryBuilder.this.createRegistration());
+            EntityRegistry.instance().insert(EntityEntryBuilder.this.entity, createRegistration());
             if (EntityEntryBuilder.this.spawns != null)
             {
                 for (final Spawn spawn : EntityEntryBuilder.this.spawns)
@@ -350,6 +341,17 @@ public final class EntityEntryBuilder<E extends Entity>
                 EntityEntryBuilder.this.spawns = null;
             }
         }
+
+        @Nonnull
+        private EntityRegistry.EntityRegistration createRegistration()
+        {
+            EntityEntryBuilder<E> builder = EntityEntryBuilder.this;
+            return EntityRegistry.instance().new EntityRegistration(
+                builder.mod, builder.id, builder.entity, builder.name, builder.network,
+                builder.trackingRange, builder.trackingUpdateFrequency, builder.trackingVelocityUpdates, this.factory
+            );
+        }
+
     }
 
     public final class Spawn

src/main/java/net/minecraftforge/fml/common/registry/EntityRegistry.java

@@ -29,6 +29,7 @@ import net.minecraft.entity.EntityLiving;
 import net.minecraft.entity.EntityTracker;
 import net.minecraft.entity.EnumCreatureType;
 import net.minecraft.util.ResourceLocation;
+import net.minecraft.world.World;
 import net.minecraft.world.biome.Biome;
 import net.minecraft.world.biome.Biome.SpawnListEntry;
 import net.minecraftforge.fml.common.FMLCommonHandler;
@@ -48,7 +49,9 @@ public class EntityRegistry
 {
     public class EntityRegistration
     {
+        @Deprecated
         private Class<? extends Entity> entityClass;
+        private Function<World, ? extends Entity> factory;
         private ModContainer container;
         private ResourceLocation regName;
         private String entityName;
@@ -58,7 +61,14 @@ public class EntityRegistry
         private boolean sendsVelocityUpdates;
         private Function<EntitySpawnMessage, Entity> customSpawnCallback;
         private boolean usesVanillaSpawning;
+
+        @Deprecated //1.13
         public EntityRegistration(ModContainer mc, ResourceLocation registryName, Class<? extends Entity> entityClass, String entityName, int id, int trackingRange, int updateFrequency, boolean sendsVelocityUpdates)
+        {
+            this(mc, registryName, entityClass, entityName, id, trackingRange, updateFrequency, sendsVelocityUpdates, null);
+        }
+
+        public EntityRegistration(ModContainer mc, ResourceLocation registryName, Class<? extends Entity> entityClass, String entityName, int id, int trackingRange, int updateFrequency, boolean sendsVelocityUpdates, Function<World, ? extends Entity> factory)
         {
             this.container = mc;
             this.regName = registryName;
@@ -68,15 +78,27 @@ public class EntityRegistry
             this.trackingRange = trackingRange;
             this.updateFrequency = updateFrequency;
             this.sendsVelocityUpdates = sendsVelocityUpdates;
+            this.factory = factory != null ? factory :
+                new EntityEntryBuilder.ConstructorFactory<Entity>(entityClass) {
+                    @Override
+                    protected String describeEntity() {
+                        return String.valueOf(EntityRegistration.this.getRegistryName());
+                    }
+                };
         }
         public ResourceLocation getRegistryName()
         {
             return regName;
         }
+        @Deprecated //Used only for creating a new instance in EntitySpawnHandler, use newInstance(world) instead.
         public Class<? extends Entity> getEntityClass()
         {
             return entityClass;
         }
+        public Entity newInstance(World world)
+        {
+            return this.factory.apply(world);
+        }
         public ModContainer getContainer()
         {
             return container;