Handle inventory max stack sizes better. Fixes BUKKIT-5564

Make sure we check the inventory's max stack size where appropriate and
don't assume the inventory slot is able to take our entire stack just
because it is empty. We also ensure the client is updated with the correct
slot contents and cursor contents in cases where the max stack changes
result in different behavior than the client expected.

1 files changed, 33 insertions, 8 deletions

diff --git a/src/main/java/net/minecraft/server/Container.java b/src/main/java/net/minecraft/server/Container.java
index bc52beb6..3443a192 100644
--- a/src/main/java/net/minecraft/server/Container.java
+++ b/src/main/java/net/minecraft/server/Container.java
@@ -282,7 +282,11 @@ public abstract class Container {
 
                                 if (itemstack4.count == 0) {
                                     playerinventory.setCarried((ItemStack) null);
+                                // CraftBukkit start - Update client cursor if we didn't empty it
+                                } else if (entityhuman instanceof EntityPlayer) {
+                                    ((EntityPlayer) entityhuman).playerConnection.sendPacket(new PacketPlayOutSetSlot(-1, -1, entityhuman.inventory.getCarried()));
                                 }
+                                // CraftBukkit end
                             }
                         } else if (slot2.isAllowed(entityhuman)) {
                             if (itemstack4 == null) {
@@ -308,7 +312,11 @@ public abstract class Container {
                                     itemstack4.a(k1);
                                     if (itemstack4.count == 0) {
                                         playerinventory.setCarried((ItemStack) null);
+                                    // CraftBukkit start - Update client cursor if we didn't empty it
+                                    } else if (entityhuman instanceof EntityPlayer) {
+                                        ((EntityPlayer) entityhuman).playerConnection.sendPacket(new PacketPlayOutSetSlot(-1, -1, entityhuman.inventory.getCarried()));
                                     }
+                                    // CraftBukkit end
 
                                     itemstack1.count += k1;
                                 } else if (itemstack4.count <= slot2.getMaxStackSize()) {
@@ -317,7 +325,10 @@ public abstract class Container {
                                 }
                             } else if (itemstack1.getItem() == itemstack4.getItem() && itemstack4.getMaxStackSize() > 1 && (!itemstack1.usesData() || itemstack1.getData() == itemstack4.getData()) && ItemStack.equals(itemstack1, itemstack4)) {
                                 k1 = itemstack1.count;
-                                if (k1 > 0 && k1 + itemstack4.count <= itemstack4.getMaxStackSize()) {
+                                // CraftBukkit start - itemstack4.getMaxStackSize() -> maxStack
+                                int maxStack = Math.min(itemstack4.getMaxStackSize(), slot2.getMaxStackSize());
+                                if (k1 > 0 && k1 + itemstack4.count <= maxStack) {
+                                    // CraftBukkit end
                                     itemstack4.count += k1;
                                     itemstack1 = slot2.a(k1);
                                     if (itemstack1.count == 0) {
@@ -325,11 +336,20 @@ public abstract class Container {
                                     }
 
                                     slot2.a(entityhuman, playerinventory.getCarried());
+                                // CraftBukkit start - Update client cursor if we didn't empty it
+                                } else if (entityhuman instanceof EntityPlayer) {
+                                    ((EntityPlayer) entityhuman).playerConnection.sendPacket(new PacketPlayOutSetSlot(-1, -1, entityhuman.inventory.getCarried()));
                                 }
+                                // CraftBukkit end
                             }
                         }
 
                         slot2.f();
+                        // CraftBukkit start - Make sure the client has the right slot contents
+                        if (entityhuman instanceof EntityPlayer) {
+                            ((EntityPlayer) entityhuman).playerConnection.sendPacket(new PacketPlayOutSetSlot(this.windowId, slot2.rawSlotIndex, slot2.getItem()));
+                        }
+                        // CraftBukkit end
                     }
                 }
             } else if (k == 2 && j >= 0 && j < 9) {
@@ -468,17 +488,20 @@ public abstract class Container {
                 if (itemstack1 != null && itemstack1.getItem() == itemstack.getItem() && (!itemstack.usesData() || itemstack.getData() == itemstack1.getData()) && ItemStack.equals(itemstack, itemstack1)) {
                     int l = itemstack1.count + itemstack.count;
 
-                    if (l <= itemstack.getMaxStackSize()) {
+                    // CraftBukkit start - itemstack.getMaxStackSize() -> maxStack
+                    int maxStack = Math.min(itemstack.getMaxStackSize(), slot.getMaxStackSize());
+                    if (l <= maxStack) {
                         itemstack.count = 0;
                         itemstack1.count = l;
                         slot.f();
                         flag1 = true;
-                    } else if (itemstack1.count < itemstack.getMaxStackSize()) {
-                        itemstack.count -= itemstack.getMaxStackSize() - itemstack1.count;
-                        itemstack1.count = itemstack.getMaxStackSize();
+                    } else if (itemstack1.count < maxStack) {
+                        itemstack.count -= maxStack - itemstack1.count;
+                        itemstack1.count = maxStack;
                         slot.f();
-                        flag1 = true;
+                        flag1 = itemstack.count == 0; // Don't give a success return if we have leftovers
                     }
+                    // CraftBukkit end
                 }
 
                 if (flag) {
@@ -502,8 +525,10 @@ public abstract class Container {
                 if (itemstack1 == null) {
                     slot.set(itemstack.cloneItemStack());
                     slot.f();
-                    itemstack.count = 0;
-                    flag1 = true;
+                    // CraftBukkit start - Don't assume entire stack went in
+                    itemstack.count -= slot.getItem().count;
+                    flag1 = itemstack.count == 0;
+                    // CraftBukkit end
                     break;
                 }