Paper/nms-patches/BlockShulkerBox.patch

--- a/net/minecraft/server/BlockShulkerBox.java
+++ b/net/minecraft/server/BlockShulkerBox.java
@@ -92,7 +92,32 @@
 
     }
 
-    public void dropNaturally(World world, BlockPosition blockposition, IBlockData iblockdata, float f, int i) {}
+    // CraftBukkit start - override to prevent duplication when dropping
+    public void dropNaturally(World world, BlockPosition blockposition, IBlockData iblockdata, float f, int i) {
+        TileEntity tileentity = world.getTileEntity(blockposition);
+
+        if (tileentity instanceof TileEntityShulkerBox) {
+            TileEntityShulkerBox tileentityshulkerbox = (TileEntityShulkerBox) tileentity;
+
+            if (!tileentityshulkerbox.r() && tileentityshulkerbox.F()) {
+                ItemStack itemstack = new ItemStack(Item.getItemOf(this));
+                NBTTagCompound nbttagcompound = new NBTTagCompound();
+                NBTTagCompound nbttagcompound1 = new NBTTagCompound();
+
+                nbttagcompound.set("BlockEntityTag", ((TileEntityShulkerBox) tileentity).f(nbttagcompound1));
+                itemstack.setTag(nbttagcompound);
+                if (tileentityshulkerbox.hasCustomName()) {
+                    itemstack.g(tileentityshulkerbox.getName());
+                    tileentityshulkerbox.setCustomName("");
+                }
+
+                a(world, blockposition, itemstack);
+            }
+
+            world.updateAdjacentComparators(blockposition, iblockdata.getBlock());
+        }
+    }
+    // CraftBukkit end
 
     public void postPlace(World world, BlockPosition blockposition, IBlockData iblockdata, EntityLiving entityliving, ItemStack itemstack) {
         if (itemstack.hasName()) {
@@ -108,7 +133,7 @@
     public void remove(World world, BlockPosition blockposition, IBlockData iblockdata) {
         TileEntity tileentity = world.getTileEntity(blockposition);
 
-        if (tileentity instanceof TileEntityShulkerBox) {
+        if (false && tileentity instanceof TileEntityShulkerBox) { // CraftBukkit - moved up
             TileEntityShulkerBox tileentityshulkerbox = (TileEntityShulkerBox) tileentity;
 
             if (!tileentityshulkerbox.r() && tileentityshulkerbox.F()) {
@@ -126,8 +151,8 @@
                 a(world, blockposition, itemstack);
             }
 
-            world.updateAdjacentComparators(blockposition, iblockdata.getBlock());
         }
+        world.updateAdjacentComparators(blockposition, iblockdata.getBlock()); // CraftBukkit - moved down
 
         super.remove(world, blockposition, iblockdata);
     }