Handle inventory max stack sizes even better. Fixes BUKKIT-5595

In 7e37cf96 we modified the container logic to handle custom max stack
sizes better and ensure the client stays in sync with this scenario. This
had the effect of sending an extra set slot packet for every inventory
click a player did which was not wanted. These extra packets also cause the
client to recalculate recipes which breaks the result slot for custom
recipes. To avoid the extra packets in general we now only send them if the
max stack is not the one we started with. In the case of a setting a custom
max stack size on a workbench this is still not enough so we also now send
another extra packet to make sure the result slot is always correct.

src/main/java/net/minecraft/server/Container.java

@@ -13,6 +13,7 @@ import org.bukkit.craftbukkit.inventory.CraftInventory;
 import org.bukkit.craftbukkit.inventory.CraftItemStack;
 import org.bukkit.event.Event.Result;
 import org.bukkit.event.inventory.InventoryDragEvent;
+import org.bukkit.event.inventory.InventoryType;
 import org.bukkit.inventory.InventoryView;
 // CraftBukkit end
 
@@ -346,8 +347,12 @@ public abstract class Container {
 
                         slot2.f();
                         // CraftBukkit start - Make sure the client has the right slot contents
-                        if (entityhuman instanceof EntityPlayer) {
+                        if (entityhuman instanceof EntityPlayer && slot2.getMaxStackSize() != 64) {
                             ((EntityPlayer) entityhuman).playerConnection.sendPacket(new PacketPlayOutSetSlot(this.windowId, slot2.rawSlotIndex, slot2.getItem()));
+                            // Updating a crafting inventory makes the client reset the result slot, have to send it again
+                            if (this.getBukkitView().getType() == InventoryType.WORKBENCH || this.getBukkitView().getType() == InventoryType.CRAFTING) {
+                                ((EntityPlayer) entityhuman).playerConnection.sendPacket(new PacketPlayOutSetSlot(this.windowId, 0, this.getSlot(0).getItem()));
+                            }
                         }
                         // CraftBukkit end
                     }