Update according to suggestions

patches/minecraft/net/minecraft/entity/EntityLivingBase.java.patch

@@ -285,7 +285,7 @@
          }
  
          this.func_184602_cy();
-@@ -2626,4 +2707,34 @@
+@@ -2626,4 +2707,27 @@
      {
          return true;
      }
@@ -300,16 +300,9 @@
 +    {
 +        if (capability == net.minecraftforge.items.CapabilityItemHandler.ITEM_HANDLER_CAPABILITY)
 +        {
-+            if (facing == net.minecraft.util.EnumFacing.UP)
++            if (facing == null) return (T) joinedHandler;
-+            {
++            else if (facing.func_176740_k().func_176720_b()) return (T) handHandler;
-+                return (T) armorHandler;
++            else if (facing.func_176740_k().func_176722_c()) return (T) armorHandler;
-+            } else if (facing.func_176740_k().func_176722_c())
-+            {
-+                return (T) handHandler;
-+            } else
-+            {
-+                return (T) joinedHandler;
-+            }
 +        }
 +        return super.getCapability(capability, facing);
 +    }

patches/minecraft/net/minecraft/entity/passive/EntityHorse.java.patch

@@ -16,7 +16,7 @@
              }
  
              this.field_70138_W = 1.0F;
-@@ -1793,4 +1795,25 @@
+@@ -1793,4 +1795,20 @@
                  this.field_188477_b = p_i46589_2_;
              }
          }
@@ -27,18 +27,13 @@
 +    @Override
 +    public <T> T getCapability(net.minecraftforge.common.capabilities.Capability<T> capability, net.minecraft.util.EnumFacing facing)
 +    {
-+        if (capability == net.minecraftforge.items.CapabilityItemHandler.ITEM_HANDLER_CAPABILITY
++        if (capability == net.minecraftforge.items.CapabilityItemHandler.ITEM_HANDLER_CAPABILITY) return (T) itemHandler;
-+                && itemHandler != null)
-+        {
-+            return (T) itemHandler;
-+        }
 +        return super.getCapability(capability, facing);
 +    }
 +
 +    @Override
 +    public boolean hasCapability(net.minecraftforge.common.capabilities.Capability<?> capability, net.minecraft.util.EnumFacing facing)
 +    {
-+        return capability == net.minecraftforge.items.CapabilityItemHandler.ITEM_HANDLER_CAPABILITY && itemHandler != null
++        return capability == net.minecraftforge.items.CapabilityItemHandler.ITEM_HANDLER_CAPABILITY || super.hasCapability(capability, facing);
-+                || super.hasCapability(capability, facing);
 +    }
  }

patches/minecraft/net/minecraft/entity/player/EntityPlayer.java.patch

@@ -401,7 +401,7 @@
  
          if (this.func_70608_bn())
          {
-@@ -2340,6 +2447,169 @@
+@@ -2340,6 +2447,160 @@
          return (float)this.func_110148_a(SharedMonsterAttributes.field_188792_h).func_111126_e();
      }
  
@@ -534,8 +534,9 @@
 +    public java.util.Collection<ITextComponent> getSuffixes() { return this.suffixes; }
 +
 +    private final net.minecraftforge.items.IItemHandler playerMainHandler = new net.minecraftforge.items.wrapper.PlayerMainInvWrapper(field_71071_by);
-+    private final net.minecraftforge.items.IItemHandler playerArmorHandler = new net.minecraftforge.items.wrapper.PlayerArmorInvWrapper(field_71071_by);
++    private final net.minecraftforge.items.IItemHandler playerEquipmentHandler = new net.minecraftforge.items.wrapper.CombinedInvWrapper(
-+    private final net.minecraftforge.items.IItemHandler playerOffhandHandler = new net.minecraftforge.items.wrapper.PlayerOffhandInvWrapper(field_71071_by);
++                    new net.minecraftforge.items.wrapper.PlayerArmorInvWrapper(field_71071_by),
++                    new net.minecraftforge.items.wrapper.PlayerOffhandInvWrapper(field_71071_by));
 +    private final net.minecraftforge.items.IItemHandler playerJoinedHandler = new net.minecraftforge.items.wrapper.PlayerInvWrapper(field_71071_by);
 +
 +    @Override
@@ -543,19 +544,9 @@
 +    {
 +        if (capability == net.minecraftforge.items.CapabilityItemHandler.ITEM_HANDLER_CAPABILITY)
 +        {
-+            if (facing == net.minecraft.util.EnumFacing.UP)
++            if (facing == null) return (T) playerJoinedHandler;
-+            {
++            else if (facing.func_176740_k().func_176720_b()) return (T) playerMainHandler;
-+                return (T) playerArmorHandler;
++            else if (facing.func_176740_k().func_176722_c()) return (T) playerEquipmentHandler;
-+            } else if (facing == net.minecraft.util.EnumFacing.DOWN)
-+            {
-+                return (T) playerMainHandler;
-+            } else if (facing.func_176740_k().func_176722_c())
-+            {
-+                return (T) playerOffhandHandler;
-+            } else
-+            {
-+                return (T) playerJoinedHandler;
-+            }
 +        }
 +        return super.getCapability(capability, facing);
 +    }

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

@@ -4,29 +4,14 @@ import net.minecraft.entity.player.InventoryPlayer;
 import net.minecraft.inventory.EntityEquipmentSlot;
 import net.minecraft.item.ItemStack;
 
-public class PlayerArmorInvWrapper extends InvWrapper
+public class PlayerArmorInvWrapper extends RangedWrapper
 {
     public final InventoryPlayer inventoryPlayer;
-    private final int offset;
 
     public PlayerArmorInvWrapper(InventoryPlayer inv)
     {
-        super(inv);
+        super(new InvWrapper(inv), inv.mainInventory.length, inv.mainInventory.length + inv.armorInventory.length);
-
         inventoryPlayer = inv;
-        offset = inventoryPlayer.mainInventory.length;
-    }
-
-    @Override
-    public int getSlots()
-    {
-        return inventoryPlayer.armorInventory.length;
-    }
-
-    @Override
-    public ItemStack getStackInSlot(int slot)
-    {
-        return super.getStackInSlot(slot + offset);
     }
 
     @Override
@@ -44,20 +29,8 @@ public class PlayerArmorInvWrapper extends InvWrapper
         // check if it's valid for the armor slot
         if (slot < 4 && stack != null && stack.getItem().isValidArmor(stack, equ, inventoryPlayer.player))
         {
-            return super.insertItem(slot + offset, stack, simulate);
+            return super.insertItem(slot, stack, simulate);
         }
         return stack;
     }
-
-    @Override
-    public void setStackInSlot(int slot, ItemStack stack)
-    {
-        super.setStackInSlot(slot + offset, stack);
-    }
-
-    @Override
-    public ItemStack extractItem(int slot, int amount, boolean simulate)
-    {
-        return super.extractItem(slot + offset, amount, simulate);
-    }
 }

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

@@ -8,54 +8,19 @@ import net.minecraft.item.ItemStack;
  * Exposes the player inventory WITHOUT the armor inventory as IItemHandler.
  * Also takes core of inserting/extracting having the same logic as picking up items.
  */
-public class PlayerMainInvWrapper extends InvWrapper
+public class PlayerMainInvWrapper extends RangedWrapper
 {
     public final InventoryPlayer inventoryPlayer;
 
     public PlayerMainInvWrapper(InventoryPlayer inv)
     {
-        super(inv);
+        super(new InvWrapper(inv), 0, inv.mainInventory.length);
-
         inventoryPlayer = inv;
     }
 
-    @Override
-    public int getSlots()
-    {
-        return inventoryPlayer.mainInventory.length;
-    }
-
-    @Override
-    public void setStackInSlot(int slot, ItemStack stack)
-    {
-        // prevent setting of armor and offhand
-        if (slot > getSlots())
-        {
-            return;
-        }
-        super.setStackInSlot(slot, stack);
-    }
-
-    @Override
-    public ItemStack getStackInSlot(int slot)
-    {
-        // prevent getting of armor and offhand
-        if (slot > getSlots())
-        {
-            return null;
-        }
-        return super.getStackInSlot(slot);
-    }
-
     @Override
     public ItemStack insertItem(int slot, ItemStack stack, boolean simulate)
     {
-        // prevent inserting into armor and offhand
-        if (slot > getSlots())
-        {
-            return stack;
-        }
-
         ItemStack rest = super.insertItem(slot, stack, simulate);
         if (rest == null || rest.stackSize != stack.stackSize)
         {
@@ -74,15 +39,4 @@ public class PlayerMainInvWrapper extends InvWrapper
         }
         return rest;
     }
-
-    @Override
-    public ItemStack extractItem(int slot, int amount, boolean simulate)
-    {
-        // prevent extraction from armor and offhand
-        if (slot > getSlots())
-        {
-            return null;
-        }
-        return super.extractItem(slot, amount, simulate);
-    }
 }

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

@@ -3,47 +3,11 @@ package net.minecraftforge.items.wrapper;
 import net.minecraft.entity.player.InventoryPlayer;
 import net.minecraft.item.ItemStack;
 
-public class PlayerOffhandInvWrapper extends InvWrapper
+public class PlayerOffhandInvWrapper extends RangedWrapper
 {
-    public final InventoryPlayer inventoryPlayer;
-    private final int offset;
-
     public PlayerOffhandInvWrapper(InventoryPlayer inv)
     {
-        super(inv);
+        super(new InvWrapper(inv), inv.mainInventory.length + inv.armorInventory.length,
-
+                inv.mainInventory.length + inv.armorInventory.length + inv.offHandInventory.length);
-        inventoryPlayer = inv;
-        offset = inventoryPlayer.mainInventory.length + inventoryPlayer.armorInventory.length;
     }
-
-    @Override
-    public int getSlots()
-    {
-        return inventoryPlayer.offHandInventory.length;
-    }
-
-    @Override
-    public ItemStack getStackInSlot(int slot)
-    {
-        return super.getStackInSlot(slot + offset);
-    }
-
-    @Override
-    public ItemStack insertItem(int slot, ItemStack stack, boolean simulate)
-    {
-        return super.insertItem(slot + offset, stack, simulate);
-    }
-
-    @Override
-    public void setStackInSlot(int slot, ItemStack stack)
-    {
-        super.setStackInSlot(slot + offset, stack);
-    }
-
-    @Override
-    public ItemStack extractItem(int slot, int amount, boolean simulate)
-    {
-        return super.extractItem(slot + offset, amount, simulate);
-    }
-
 }

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

@@ -0,0 +1,78 @@
+package net.minecraftforge.items.wrapper;
+
+import com.google.common.base.Preconditions;
+import net.minecraft.item.ItemStack;
+import net.minecraftforge.items.IItemHandlerModifiable;
+
+/**
+ * A wrapper that composes another IItemHandlerModifiable, exposing only a range of the composed slots.
+ * Shifting of slot indices is handled automatically for you.
+ */
+public class RangedWrapper implements IItemHandlerModifiable {
+
+    private final IItemHandlerModifiable compose;
+    private final int minSlot;
+    private final int maxSlot;
+
+    public RangedWrapper(IItemHandlerModifiable compose, int minSlot, int maxSlotExclusive)
+    {
+        Preconditions.checkArgument(maxSlotExclusive > minSlot, "Max slot must be greater than min slot");
+        this.compose = compose;
+        this.minSlot = minSlot;
+        this.maxSlot = maxSlotExclusive;
+    }
+
+    @Override
+    public int getSlots()
+    {
+        return maxSlot - minSlot;
+    }
+
+    @Override
+    public ItemStack getStackInSlot(int slot)
+    {
+        if (checkSlot(slot))
+        {
+            return compose.getStackInSlot(slot + minSlot);
+        }
+
+        return null;
+    }
+
+    @Override
+    public ItemStack insertItem(int slot, ItemStack stack, boolean simulate)
+    {
+        if (checkSlot(slot))
+        {
+            return compose.insertItem(slot + minSlot, stack, simulate);
+        }
+
+        return stack;
+    }
+
+    @Override
+    public ItemStack extractItem(int slot, int amount, boolean simulate)
+    {
+        if (checkSlot(slot))
+        {
+            return compose.extractItem(slot + minSlot, amount, simulate);
+        }
+
+        return null;
+    }
+
+    @Override
+    public void setStackInSlot(int slot, ItemStack stack)
+    {
+        if (checkSlot(slot))
+        {
+            compose.setStackInSlot(slot + minSlot, stack);
+        }
+    }
+
+    private boolean checkSlot(int localSlot)
+    {
+        return localSlot + minSlot < maxSlot;
+    }
+
+}