PaperMC/nms-patches/ItemEnderPearl.patch

--- a/net/minecraft/server/ItemEnderPearl.java
+++ b/net/minecraft/server/ItemEnderPearl.java
@@ -9,18 +9,26 @@
     public InteractionResultWrapper<ItemStack> a(World world, EntityHuman entityhuman, EnumHand enumhand) {
         ItemStack itemstack = entityhuman.b(enumhand);
 
+        // CraftBukkit start - change order
+        if (!world.isClientSide) {
+            EntityEnderPearl entityenderpearl = new EntityEnderPearl(world, entityhuman);
+
+            entityenderpearl.a(entityhuman, entityhuman.pitch, entityhuman.yaw, 0.0F, 1.5F, 1.0F);
+            if (!world.addEntity(entityenderpearl)) {
+                if (entityhuman instanceof EntityPlayer) {
+                    ((EntityPlayer) entityhuman).getBukkitEntity().updateInventory();
+                }
+                return new InteractionResultWrapper(EnumInteractionResult.FAIL, itemstack);
+            }
+        }
+
         if (!entityhuman.abilities.canInstantlyBuild) {
             itemstack.subtract(1);
         }
 
         world.a((EntityHuman) null, entityhuman.locX, entityhuman.locY, entityhuman.locZ, SoundEffects.ENTITY_ENDER_PEARL_THROW, SoundCategory.NEUTRAL, 0.5F, 0.4F / (ItemEnderPearl.i.nextFloat() * 0.4F + 0.8F));
         entityhuman.getCooldownTracker().a(this, 20);
-        if (!world.isClientSide) {
-            EntityEnderPearl entityenderpearl = new EntityEnderPearl(world, entityhuman);
-
-            entityenderpearl.a(entityhuman, entityhuman.pitch, entityhuman.yaw, 0.0F, 1.5F, 1.0F);
-            world.addEntity(entityenderpearl);
-        }
+        // CraftBukkit end
 
         entityhuman.b(StatisticList.ITEM_USED.b(this));
         return new InteractionResultWrapper<>(EnumInteractionResult.SUCCESS, itemstack);