More patch work, our async chunk loading doesn't appear to be viable for 1.13.

src/main/java/net/minecraftforge/common/ForgeConfig.java

@@ -75,20 +75,19 @@ public class ForgeConfig
             .translation("forge.configgui.fixVanillaCascading")
             .define("fixVanillaCascading", false)
 
-
             .comment("The time in ticks the server will wait when a dimension was queued to unload. This can be useful when rapidly loading and unloading dimensions, like e.g. throwing items through a nether portal a few time per second.")
             .translation("forge.configgui.dimensionUnloadQueueDelay")
             .defineInRange("dimensionUnloadQueueDelay", 0, 0, Integer.MAX_VALUE)
+
+            .comment("Controls the number threshold at which Packet51 is preferred over Packet52, default and minimum 64, maximum 1024")
+            .translation("forge.configgui.clumpingThreshold")
+            .worldRestart()
+            .defineInRange("clumpingThreshold", 64, 64, 1024)
         .pop()
 
         //Client
         .comment("Client only settings, mostly things related to rendering")
         .push("client")
-            .comment("Controls the number threshold at which Packet51 is preferred over Packet52, default and minimum 64, maximum 1024")
-            .translation("forge.configgui.clumpingThreshold")
-            .worldRestart()
-            .defineInRange("clumpingThreshold", 64, 64, 1024)
-
             .comment("Toggle off to make missing model text in the gui fit inside the slot.")
             .translation("forge.configgui.zoomInMissingModelTextInGui")
             .define("zoomInMissingModelTextInGui", false)
@@ -149,8 +148,11 @@ public class ForgeConfig
         public static double zombieBaseSummonChance() {
             return ForgeConfig.INSTANCE.configData.<Double>getOrElse("general.zombieBaseSummonChance", (double)0.01F);
         }
-        public static float zombieBabyChance() {
-            return ForgeConfig.INSTANCE.configData.<Float>getOrElse("general.zombieBabyChance", 0.05F);
+        public static double zombieBabyChance() {
+            return ForgeConfig.INSTANCE.configData.<Double>getOrElse("general.zombieBabyChance", 0.05D);
+        }
+        public static int clumpingThreshold() {
+            return ForgeConfig.INSTANCE.configData.<Integer>getOrElse("general.clumpingThreshold", 64);
         }
     }
 

src/main/java/net/minecraftforge/common/extensions/IForgeBlockState.java

@@ -31,6 +31,7 @@ import net.minecraft.entity.EntityLivingBase;
 import net.minecraft.entity.EntitySpawnPlacementRegistry.SpawnPlacementType;
 import net.minecraft.entity.player.EntityPlayer;
 import net.minecraft.fluid.IFluidState;
+import net.minecraft.init.Blocks;
 import net.minecraft.item.EnumDyeColor;
 import net.minecraft.item.Item;
 import net.minecraft.item.ItemStack;

src/main/java/net/minecraftforge/common/extensions/IForgeItem.java

@@ -34,7 +34,6 @@ import net.minecraft.entity.item.EntityItem;
 import net.minecraft.entity.passive.EntityHorse;
 import net.minecraft.entity.passive.HorseArmorType;
 import net.minecraft.entity.player.EntityPlayer;
-import net.minecraft.entity.player.EntityPlayerMP;
 import net.minecraft.init.Items;
 import net.minecraft.inventory.EntityEquipmentSlot;
 import net.minecraft.item.IItemPropertyGetter;
@@ -42,7 +41,6 @@ import net.minecraft.item.Item;
 import net.minecraft.item.ItemAxe;
 import net.minecraft.item.ItemGroup;
 import net.minecraft.item.ItemStack;
-import net.minecraft.item.ItemSword;
 import net.minecraft.item.ItemUseContext;
 import net.minecraft.nbt.NBTTagCompound;
 import net.minecraft.util.EnumActionResult;
@@ -50,7 +48,6 @@ import net.minecraft.util.ResourceLocation;
 import net.minecraft.util.math.BlockPos;
 import net.minecraft.util.math.MathHelper;
 import net.minecraft.util.registry.RegistrySimple;
-import net.minecraft.world.GameType;
 import net.minecraft.world.World;
 import net.minecraftforge.api.distmarker.Dist;
 import net.minecraftforge.api.distmarker.OnlyIn;
@@ -329,16 +326,14 @@ public interface IForgeItem
      * Determines if the specific ItemStack can be placed in the specified armor
      * slot, for the entity.
      *
-     * TODO: Change name to canEquip in 1.13?
-     *
      * @param stack     The ItemStack
      * @param armorType Armor slot to be verified.
      * @param entity    The entity trying to equip the armor
      * @return True if the given ItemStack can be inserted in the slot
      */
-    default boolean isValidArmor(ItemStack stack, EntityEquipmentSlot armorType, Entity entity)
+    default boolean canEquip(ItemStack stack, EntityEquipmentSlot armorType, Entity entity)
     {
-        return net.minecraft.entity.EntityLiving.getSlotForItemStack(stack) == armorType;
+        return EntityLiving.getSlotForItemStack(stack) == armorType;
     }
 
     /**
@@ -739,6 +734,7 @@ public interface IForgeItem
      * @return an enum constant of type {@code HorseArmorType}. Return
      *         HorseArmorType.NONE if this is not horse armor
      */
+    @SuppressWarnings("deprecation")
     default HorseArmorType getHorseArmorType(ItemStack stack)
     {
         return HorseArmorType.getByItem(stack.getItem());

src/main/java/net/minecraftforge/common/extensions/IForgeItemStack.java

@@ -26,16 +26,15 @@ import javax.annotation.Nullable;
 import net.minecraft.block.state.BlockWorldState;
 import net.minecraft.block.state.IBlockState;
 import net.minecraft.enchantment.Enchantment;
+import net.minecraft.entity.Entity;
 import net.minecraft.entity.EntityLiving;
 import net.minecraft.entity.EntityLivingBase;
 import net.minecraft.entity.item.EntityItem;
 import net.minecraft.entity.passive.EntityHorse;
 import net.minecraft.entity.passive.HorseArmorType;
 import net.minecraft.entity.player.EntityPlayer;
-import net.minecraft.init.Items;
 import net.minecraft.inventory.EntityEquipmentSlot;
 import net.minecraft.item.Item;
-import net.minecraft.item.ItemAxe;
 import net.minecraft.item.ItemStack;
 import net.minecraft.item.ItemUseContext;
 import net.minecraft.nbt.NBTTagCompound;
@@ -145,7 +144,7 @@ public interface IForgeItemStack extends ICapabilitySerializable<NBTTagCompound>
      */
     default boolean onBlockStartBreak(BlockPos pos, EntityPlayer player)
     {
-        return getStack().isEmpty() || getStack().getItem().onBlockStartBreak(getStack(), pos, player);
+        return !getStack().isEmpty() && getStack().getItem().onBlockStartBreak(getStack(), pos, player);
     }
 
     /**
@@ -300,4 +299,39 @@ public interface IForgeItemStack extends ICapabilitySerializable<NBTTagCompound>
     {
         getStack().getItem().onHorseArmorTick(getStack(), world, horse);
     }
+
+    /**
+     * Whether this Item can be used as a payment to activate the vanilla beacon.
+     *
+     * @return true if this Item can be used
+     */
+    default boolean isBeaconPayment()
+    {
+        return getStack().getItem().isBeaconPayment(getStack());
+    }
+
+    /**
+     * Determines if the specific ItemStack can be placed in the specified armor
+     * slot, for the entity.
+     *
+     * @param armorType Armor slot to be verified.
+     * @param entity    The entity trying to equip the armor
+     * @return True if the given ItemStack can be inserted in the slot
+     */
+    default boolean canEquip(EntityEquipmentSlot armorType, Entity entity)
+    {
+        return getStack().getItem().canEquip(getStack(), armorType, entity);
+    }
+
+    /**
+     * Allow or forbid the specific book/item combination as an anvil enchant
+     *
+     * @param stack The item
+     * @param book  The book
+     * @return if the enchantment is allowed
+     */
+    default boolean isBookEnchantable(ItemStack book)
+    {
+        return getStack().getItem().isBookEnchantable(getStack(), book);
+    }
 }

src/main/java/net/minecraftforge/items/wrapper/PlayerArmorInvWrapper.java

@@ -49,7 +49,7 @@ public class PlayerArmorInvWrapper extends RangedWrapper
             }
         }
         // check if it's valid for the armor slot
-        if (equ != null && slot < 4 && !stack.isEmpty() && stack.getItem().isValidArmor(stack, equ, getInventoryPlayer().player))
+        if (equ != null && slot < 4 && !stack.isEmpty() && stack.canEquip(equ, getInventoryPlayer().player))
         {
             return super.insertItem(slot, stack, simulate);
         }