craftbukkit/nms-patches/net/minecraft/world/entity/projectile/EntityFireballFireball.patch

--- a/net/minecraft/world/entity/projectile/EntityFireballFireball.java
+++ b/net/minecraft/world/entity/projectile/EntityFireballFireball.java
@@ -58,7 +58,12 @@
     public void readAdditionalSaveData(NBTTagCompound nbttagcompound) {
         super.readAdditionalSaveData(nbttagcompound);
         if (nbttagcompound.contains("Item", 10)) {
-            this.setItem((ItemStack) ItemStack.parse(this.registryAccess(), nbttagcompound.getCompound("Item")).orElse(this.getDefaultItem()));
+            // CraftBukkit start - SPIGOT-5474 probably came from bugged earlier versions
+            ItemStack itemstack = (ItemStack) ItemStack.parse(this.registryAccess(), nbttagcompound.getCompound("Item")).orElse(this.getDefaultItem());
+            if (!itemstack.isEmpty()) {
+                this.setItem(itemstack);
+            }
+            // CraftBukkit end
         } else {
             this.setItem(this.getDefaultItem());
         }